This Review is based on the Mad Dog 3.2 w/ Alpha Pads.
 
Sound: 
Probably one of the best things about these headphones is the sound. I absolutely love this sound signature, and I must say I would have a really hard time switching back to a dynamic driver headphone. I may be stuck in the planar magnetic headphone world for ever. I love how quick these headphones deliver sound and it restrains it from producing over pronounced sounds. For instance while the bass quantity is far from a bass head phone (which is good for me) the quality of bass far exceeds pretty much any headphone I have ever heard (though I do have a limited experience). The bass produces a quick snap, and a incredibly satisfying punch. I listen to a wide variety of music, and Metal is one of them. Within Metal songs lately have a lot of emphasis on the double bass pedal of the drums, and these headphones are a blast to listen to when the drummer is whacking a way on the pedals. The presentation of the music is incredibly pleasant to my ears as most headphones either have too forward of vocals or too forward of instruments which often causes one to drown out the other. However these phones balance both perfectly to my ears, and allows me to hear the intricate details of both vocals and instruments. Techno music and rap/hip hop (sorry I do not listen pop) are a mixed bag for these headphones. Either the bass picks up really well and there is a clean sounding melody throughout the song or there is a bland sound with a lack of bass. One album it particularly excels in is Get Lucky by Daft Punk. I hated this album, as I found quite boring. However when I started playing these through the mad dogs it became musical bliss and strangely What is Love from the A Night at the Roxbury soundtrack is a blast to listen to. I will not comment on the sound stage as my current gear is too limiting for it but I have heard the potential and it quite good. Acoustic based music is amazing through these headphones. I do not listen to much classic music (not that I hate it, just not entirely my thing), but I do listen to Apocalyptica. Their Cellos harmonize so well and create a soothing sound that draws me in every time I listen to them. Other songs like Broken from Seether (w/out Amy Lee) and the Bleeding Acoustic version from Five Finger Death Punch also sound very very very good.
 
Overall this sound signature is probably THE sound signature I have been in search for quite some time.
 
Amplification/ Source Gear:
I think people over emphasize how much gear you need with this to have a good sound. Now I am not saying that these don't scale with gear, quite the opposite. I just think that people over emphasize what the minimum requirement you should have. I do agree you NEED an amp if listening out of an ipod. As if you are looking to run these unamped its doable but nothing special and you should probably look elsewhere (MD1R1, Momentums, K550, etc.). However I had good luck with using a FIIO E17 and driving these to a respectable level. I am currently using an E12 and I find these headphones incredibly enjoyable even with the added warmness of the amp and the small sound stage. I do not find the extra warmness to be that bad, but perhaps it is because I am used to a high end warm sounding sound system. What I find the most annoying is the closed in sound stage. I have heard glimpses of what it could be and I gotta say I want the extra sound stage and separation. I also hear remnants of what it could be on higher end gear and I gotta say it is incredibly enjoyable, hence why I am going to seek out either a Colorfly C4 or Ibasso DX100. These headphones WILL bring out weaknesses in your recordings or source gear.
 
In conclusion though I do not find that you need the best of the best to get an enjoyable sound, but I find that the better the gear the better these scale. If you are on the almighty budget buy the E12 over the E17. These headphones will eat all the extra power it can get. I do get a bit of sibilance on the E12 on 16 gain around the 3/4 point on the dial but that is pretty loud and do not recommend listening to those volumes anyways. I listen to them consistently on the half way point of the volume knob.
 
Build Quality:
Probably the only thing that Mr. Speakers has not changed. I find these to be very solid. However I do not like the brass sliders as it is hard to keep your cans in the same place use after use, and sometimes one slider will tilt to one side leaving an awkward headband appearance on the top of you head. I also find the ball like joints between the sliders and the cups to be a bit wobbly when extended out to far. Over all though it is an amazingly solid headphone at any price. I am happy that Mr.Speakers is now painting on the logos now instead of stickers (I hate stickers).
 
Comfort:
I could just leave this as BEST COMFORT EVER, but I wont. I find the alpha pads to be incredibly soft and squishy and incredibly comfortable with amazing isolation. The clamping force is perfect and can be adjusted. The comfort strap is quite comfortable in the way it distributes the force on my head. However the leather strap made my head kinda itchy. I came across another person who claimed that and some people suggested that the person either had a fine leather allergy or the length of my hair may be interfering with the strap. Either way I picked up the replacement/upgrade headband off amazon http://www.amazon.com/gp/product/B00862522A/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1 and it fixed all my problems with adding a bit of extra comfort (impossible I know). The replacement does not fit perfectly as the band is too wide, but it works well even with only a few clasps clasped. I did need to readjust the band otherwise the pads pinched my head a bit. It took about 5 min to readjust and I am more than happy with the results.
 
Isolation:
My one requirement for headphones is that it must isolate. These Isolate very well and I wear them at college all the time (while looking like a dork, I don't care Ill make the sacrifice). I am never in an area where I don't have extra noise plowing into my headphones or where I would be bugging other people. I get that people don't want to listen to my music and I respect that. If I had a good place to isolate my self. I might have sought out the HE series instead or maybe even the HD650s but I don't and that is probably why my end game headphone is somewhat limited at this point. My end game is most likely the Alpha Dogs, overall sound endgame is definitely the audeze LCD 3 but without Isolation I just can not buy them.
 
Conclusion:
Overall buy these headphones if you need an isolating headphone and you like the neutral sound signature of an planar magnetic headphone.
 
Kudos to you Mr.Speaker for actually creating an amazing sounding well isolating headphone. I really hope you change the headphone world from a near fully non isolated headphone high end to a few extra options for us that need isolation. I do understand there are a couple solutions but they are not perfect (too high of a price for sound, or should isolate better).  I can not wait to hear the alpha dogs. 

I see a lot of people saying how overrated these headphones are lately, but most of the time these people compare these headphones 50% to twice its price or higher. In my opinion the ATH M50s are one hard to beat package for a beginner looking to get into better audio at a cheaper price. These headphones are better than many retail stores headphones that cost twice as much or more. I have been using these headphones for hundreds of hours over the past 2 years and have finally upgraded to the Mad Dogs (which blow these out of the water in the majority of categories).
 
Sound:
I do not think these are balanced or flat sounding like some people claim, these headphones do have an easy to listen to sound signature especially for a beginner or some one on a budget. Where these headphones excel is definitely in the lower frequencies. However being a huge fan of these the sound has a major flaw, and that is the highs. These headphones have a lot of sibilance even from uncompressed 16/44.1 files from ipod. Some of my favorite bands like Skillet and System of a Down are nearly un-listenable on these headphones. However many types of rock sound pretty good on these headphones, and they excel at Dubstep and rap. I find instrumental type music to be kinda boring on these headphones. The sound stage is quite small which make these a poor choice for gaming and movies even though these headphones have a fun sound (imo). 
 
Amplification:
These headphones do not require amplification, however I do find the ipod amplifier quite lacking (if you are using an ipod). I ended up buying and trying some of the fiio amps. The fiio amps do provide a little bit of extra juice for the driver and it helps the sound a decent amount. The LOD cable definitely probably makes the biggest difference (and is a must have if you are buying an amp for the ipod). Overall if you need a little extra sound without going to a new headphone an amplifier may be helpful.
 
Isolation: 
It is pretty decent but starts to get worse as the pads get older and start cracking. 
 
Build Quality:
Top notch for a plastic headphone at around $100. These things are nearly unbreakable. The only broken pair I have ever seen was a pair with a dog chewed cable. One thing I would like to bring up is that not all the headphones are built equally. My headphones sound quite a bit better than my brothers (same box), but mine are a year older and have been played much more. This either proves a) that burn in does make a difference in some headphones and is not a myth or b) not all the M50s batches sound the same. Another complaint is that the cable choices are annoying. Either you have a obnoxiously long cable which is annoying for portable use or you have an annoying coiled cable (imo). I chose the straight cable and to limit the length I braided the cable like you do with hair and it reduces the cable to a 1/3 of its length and is much more manageable
 
Conclusion:
You may be questioning why I gave these 5 stars after all the complaints I had in this review. Well I must say while the sound is not perfect and definetely what I would not consider an audiophile sound headphone but more of a fun one (get the SR80i if you want a cheap audiophile sound), the build, decent sound, and price is what helps this earn the 5 stars.  I see them for what they are a great beginner headphone. There are better sounding headphones for a bit more cash ($50-$100) but for somebody on a budget that extra cash is a lot of money. Overall I recommend these headphones to all my friends trying to get into audio and try to prevent them from buying an over price consumer headphone.