I'm not an audiophile (I just like to lurk here), so take this with a grain of salt, but here are my initial impressions from testing them out for the first time last night:
So far, I'm quite satisfied. The surround sound simulation worked fairly well with BF3 and Infamous 2. I could distinguish the direction of sounds all around me, as well as depth.
It's a fairly fun headset without the bass being too overbearing (even with the pulsing base impact feature turned off). It has a good balance for my needs of using them for both gaming and movies/TV. The highs are clear enough to hear footsteps and other small details useful in shooters, but it still has enough mids and bass to immerse you in a movie. The Game EQ setting felt the most neutral to me, but I'll have to test the other modes more. I'd still like to find a setting where the bass is reduced a tad, but it's not a deal breaker.
Compared to the Tritton 720+ headset - which I previously owned but returned because of a bad buzzing sound - I'd say Sony's VSS is just a slight downgrade compared to Dolby Headphone processing. But the difference is really negligible for non-competitive gaming. Bonus for these though is that the noise floor when hooked up to the PS3 is pretty much zero as far as I could hear.
Comfort-wise, I played for a few hours last night and these felt pretty good. Ideally I would have preferred velour/cloth earpads, as I can see these faux leather pads getting hot in the summer. The clamping force also could be a bit lighter, but it didn't bother me really. The clamping force on the Tritton 720+ headset was terribly tight in comparison.
The wireless connection was perfect, with the exception of when I tried powering the usb dongle on my TV's back usb ports to wirelessly watch TV using the dongle's 3.5mm jack. That caused a few sound drops, but was fixed by using a usb extension cable to bring the dongle out in front of the TV.
I'm pleasantly surprised by the pulse feature. It's much better than what your standard controller rumble feels like. I was expecting to always leave it off, but in certain situations actually did add to the immersion. I won't always use it, but will definitely turn it on at a low setting in some games and movies. As good as it works, I'd expect that the PS4 controllers will use this pulsing technology to replace the rumble that are in the DS3 controllers now.
It's a minor disappointment for me that VSS only works through the PS3, but the 3.5mm input on the dongle works well enough for TV viewing. I didn't notice much difference in sound quality through the 3.5mm input, but I'll have to test more.
Are these the best headsets you can get? No. But they're a pretty good bang for your buck, and very convenient for PS3 users.