This was my first step into Hi-Fi audio so this reveiw should be taken with a little salt.
First off if you are a bass head run from these headphones! If you like RnB, Jazz or anything with a similar sound profile you will be very happy with these. There not neutral ( there seems to be a nice bump in the mids and treble can be a bit intense, bass i will mention later), they like a good source so phones and Ipod's (imo) are out. I definitely made the mistake of using my old phone to power these on my way to work. 
 
The grip is tight, VERY tight. They feel a little crushing sometimes for prolonged listening unless you stretch them over something (I used my Mackie MR5 mk2 for about an hour). Once the fit is sorted out the are excellent! Super light too, after you have them snug on your head you will forget about them (unless ear crushing occurs).
 
Sound:
 
Treble is nice,the majority of music I listen to isn't really very treble intense but where it did come up i was quite happy.
 
Mids are beautiful! Listening to the Wookie remix of Soul 2 Soul's Fairplay is amazing due to the presence of all the vocals and the clean snap of the snare. BUT....
 
The Bass present on said song is very shy especially compared to warmer headphones.
 
All in all an excellent headphone for entry level Hi-Fi IF your not a bass head and you take the time to stretch them over something and burn them in a little

I got them today but I was able to give them a 4 hour listening sesh immediately. I A, B, C, veiwed them againstthe Shure srh440, Pioneer HDJ1500 and Apex HP96. The first thing I noticed was the lightweight but nice grip similar to the SRH440 in feel but not as tight as the Pio`s. The clarity is on par with the SRH`s and clearly ahead of both the Pioneer and Apex offerings. Also the bass that I missed in the Shure`s was present and clear immediately in the sony`s but it didn`t have the depth or slight mud of the pioneer`s and apex headphones (the Pioneer`s sound almost identical to the Apex`s even though the Apex set is half the price). Those where the main reasons I choose the Sony`s.
 
During my 4 hour set with them I quickly realized that I was wearing sound gold.
I listen to a lot of Bass heavy music that has a lot of upper mid, treble and subtle background noise.
I tested them with:
Burial- You Hurt Me
Skream-Colorful
Benga-Evolution
Clams Casino-I`m God
Kanye West-Addictions
 
I definitely did they whole ``heard new things`` moment through out all songs. But `You Hurt Me`` stood out the most because of the subtleties I now heard in the backgrounds of the song. 
 
It`s super comfortable for long sessions because of its light weight, and because its very simply built with a leather headband, metal arms and hard plastic cups it acheives the feeling of being battle ready.
Also, they caused no ear fatigue. 
 
Though my AKG K172`s might have more clarity it lacks the bass and comfort of the MDR-7509`s. My DT770 pro80`s may have more bass and similar comfort level, their to hot and heavy for portability, plus their a little to power hungry.
 
An excellent portable can all in all. I would pay $210 for these for sure so $85(used)-$150(new in canada) is a steal.