[rhalf]

Lol, am I the only one who thinks that charts from this topic are somewhat upside down?
I mean come on! PX100 best for their SQ? This thing has terribly muddy bass, super thin midrange and a complete lack of detail. It's good for their headband construction, but the cable is weak. I repair those things quite often.
 
Aiaiai tracks are another one. They have more detail then Senns, but hey! they're bass oriented and even though it isn't bloated as much as on PX100s, it affects the midrange to some small degree. Not to mention cable on theese things is among the thinnest out there, rubber material has short lifespan in comparison to Jays and PX100 and they're the hardest to repair (they require different procedure then a typical cans).
 
Vjays on the other hand have quite smart construction and sound with arguably the best resolution and instrument separation among the three and last but not least almost flat frequency response topped only by px200-II , but not at this level of detail.. Cable is also the thickest on the outside.

 

[TheAttorney]

Funnily enough, I exchanged some posts with postrock much earlier in this thread, where my views on the PX-100 and V-Jays were more or less the exact opposite of his (I much preferred the V-Jays for the same reasons as he preferred the Senns). Maybe there's considerable sample variation?
 
But whatever the reason, it just goes to show that, no matter how well anyone presents a review and rating (and postrock did it really well), it is no guarantee that anyone else will come to the same conclusion.

 

[dweaver]

I have owned both VJay and now PX100 II and I, like the OP prefer the PX100. I generally like mid/treble centric headphones but for me treble is a 2 edged sword if it goes over the edge towards to bright and brittle or sibilant which is how I heard the Vjays. The PX100 on the other hand while a bit subdued in the treble area is just so darn euphonic for my music choices. Pink Floyd in particular is great. But I will admit I have nothing beat heavy in my music genres.

 

[rhalf]

Do you think it might be bacause of the environment you use to listen to them in? I mean they're supraaural portables, so if you use them in noisy surroundings you'd need a low end hump to compensate for lost frequencies. Vjays are pretty flat for that matter. They sound like supposed more for indoor use. That's why using "hi-fi" to describe PX's sound is not really convincing to me, because they're not the ones closest to this title. But apart from their FR I'd say that Aiaiai sounds more dynamic to me than Senns, but both Vjays and Oldskool top Aiaiai in this regard.
 
By the way Philips SHL9700 are similar to Vjays, but have warmer, U shaped sound with quite deep bass. Not sure about the pricing in other countries, but in Poland they're a very good deal at about $35. I suppose they have SHP5401 drivers. At least the soundstage is the same (very good).

 

[postrock]

FOLLOW UP
Wow, it's hard to believe it's been almost 2 1/2 years since I first posted this roundup! I haven't been around much since then, work and family commitments have made it hard to put in the time and effort to do these reviews. I thought it might be useful to give you some of my impressions on all of these headphones (including those I intended to review) after having them for a few years. I still commute daily so all of these have had major "field testing".
So, from my original roundup, here are some thoughts on a few of them...
Sennheiser PX-100 II 
Interestingly, while these have held up beautifully I'm not as enamored with them as I once was. I still like them but these days I find them a bit dull. They have almost become too warm with hundreds of hours of use. A few months after my reviews I got a pair of Sennheiser HD-239 these are now among my favorites...vastly different sounding than the PX-100 II. More on those below.
AIAIAI Tracks
Still sounding really good and have held up well. I'll never be a fan of the weird design as they never feel quite right on the head but the SQ is good, if a little bass heavy.
Jays V-Jays
Even though I gave them significant burn in time, they still sounded a bit too harsh. Maybe I just had a bad pair. I've since given them away to a friend who likes them.
Koss PortaPro
Still working great. I enjoy using them on warm days when I don't mind the lack of isolation or the heavy bass. 
Fisher Audio Old Skool 70's
These have shown the biggest change since my review. They seemed to take ages to to burn in properly. I really enjoy them now. Bass response has improved and they're much fuller sounding. If you like the Grado type sound these are very close for an ultra-portable "walkman" type headphone. Of course they are out of production and really hard to find.
Incase Pivot
Sadly, these broke a while ago. Many reviewers had complained about the poor design of the earcups attaching to the headband and mine finally cracked. Impossible to repair. Too bad, they sounded really nice. Since that time, Incase have stopped making headphones. Amazingly, ALL THREE models I had (Pivot, Reflex, and Sonic) have broken. Which is really a shame in the case of the Sonic (full size over-the-ear) as they were quite incredible sounding and really comfortable. The Reflex had the same problem as the Pivot. The Sonic had a cable issue (lost signal on one side) which has proven really difficult to repair. The Sonic can still be found on eBay for about $70.00 and if you're really careful with them it's a worthwhile risk. They are fantastic.

OTHER HEADPHONES I HAD HOPED TO REVIEW
I had planned to review a whole slew of mid-sized headphones and simply could not find the time. But there are a few that really stand out that I wanted to share some impressions...
Sennheiser HD-239
Really impressive. They are very full and balanced sounding, extremely comfortable, and very forgiving of whatever your source is. My only gripe with them is the woefully thin and slightly too long cable. It seems so likely to fail but I have used them extensively for two years with no problem yet, so who knows?
Ultrasone HFI-15G
Perhaps a little overpriced for what they are, but these have become my favorite "lounging around the house" headphone.They're ridiculously comfortable and the sound quality is very "hi-fi". They now come with a shorter cable so they're better with portable devices but they offer almost no isolation from outside noise so they're not good for commuting or outdoor use. Great little headphone.
German Maestro GMP 160
A truly oddball headphone with impressive sound. These too feel almost non-existent when wearing. They weigh almost nothing. The sound quality is quite stunning in terms of detail. I hear things with these that I never heard before in many recordings. They are not without their shortcomings though. The fit is a bit too loose and the molded plastic headband cannot really be bent or adjusted. They are a little thin in terms of bass response. The cable is a little thin and too long for many uses. But the SQ is very close to audiophile. The drivers are just amazing and I would love to try some of German Maestro (formerly MB Quart) more substantial headphones.
Superlux 631
Marketed as DJ headphones but not really. As with most Superlux products the drivers are top notch (they OEM for many brands). These either fit you properly or they don't as there is almost no adjustment capability in the design. Of all the bass-heavy headphones I've heard these have the most impressive mids and really great highs. Just a fantastic sounding headphone that is surely off most people's radar. They're very affordable if you can find them on Amazon or eBay.
Beyerdynamic DTX 501p
Maybe my all-time favorite commuter headphone. Great sound quality (they have the Beyerdynamic sound signature for sure), extremely comfortable, and really impressive isolation for such a small headphone. But they are a little bit fragile and i would recommend using the included hard case when traveling with them. Mine have seen a lot of use and the outside of the earcups are very prone to scratch and also a small piece of the headband (not structurally essential) has popped of of both sides. But these are killer and worth the price.
House of Marley Positive Vibration
I tried out all of the first generation HOM headphones and this was the only model I liked. The others were all bland and dull sounding. But this model has good highs, decent balance, good comfort and good build quality. I use mine a lot. A really good sounding and affordable headphone, although a bit silly looking.
Noontec Zoro
These have come way down in price since they launched some newer models. If you can live with the fact that the design is a BLATANT Beats rip, then you have a great headphone. They look almost exactly like Beats Solo and many people will comment or even tell you that you bought a "fake" Beats! SQ is extremely good though. They're a bit hyped but really great sounding and comfortable. If all you care about is the sound quality these are a steal at approx. $50. They are really solid too and will take a lot of abuse, but you may want to or need to replace the detachable "flat" cable. Highly recommended. Amazingly, the newer models from this company (Zoro II and Hammo) also look a LOT like Beats. Too bad...
 
 
There are many others that for various reasons did not impress me. These would include:
 
SOL Republic Tracks HD
AIAIAI Capital
California Headphone Company Laredo
NOCS NS-700 Phaser
Brainwavz HM3
Eskuche 33i
JVC HA-M750 and HA-S600
RHA CA-200 and SA950i
Soniq Nitro
 
Some of these are quite decent but just did not stand out for any reason, especially vs. their competition. If anyone has specific questions about anything I mentioned in this post, please reply and I'll be happy to elaborate.
 
Thanks Head-Fiers!

 

[justgotlucky123]

Wow! It's really nice to have a follow up review on headphone reviews. All reviewers should do this!

 

[getclikinagas]

Excellent post!
Thanks for the follow-up @postrock.