Ok, so I've spent an hour or so A/Bing these with the regular TMA-1s now, and I'll post some initial impressions (I'm not really an expert at this, so please bear with me. For reference, the headphones I'm most familiar with are the TMA-1s, Senn HD 280s, and Koss Porta-Pros).
Packaging
Beautiful, as you'd expect from a company so focused on design. Very similar, in fact, to the packaging of the regular TMA-1.
Build Quality/Feel
These things are built in pretty much the same way as the originals, and seem like they should be just as sturdy, for the most part. I'm not as confident that the PU foam earpads will hold up to wear, but I guess we can wait and see on that one. As far as comfort goes, these headphones feel great on the head (with the PU earpads, at least. I have yet to try the pleather ones). The extra-padded headband is a welcome addition and the foam earcups sit very lightly over the ears.
Sound
Now the most important area, and the one which surprised me the most. I hate to say it, but on first listen I'm pretty disappointed. These things sound basically the opposite of what I expected considering they were pitched as a TMA-1 that was tuned for a more balanced sound. These headphones are DARK. While I think they have pretty good clarity overall, the low end overpowers everything. Perhaps some equalizing would take care of this, but I'd rather have something that gave me a more neutral sound out of the box.
Here are some rough impressions I wrote while listening to some of the songs I was A/Bing with:
The House that Heaven Built - Japandroids
Upper mid-range and treble seem subdued compared to regular TMAs, which surprises me. I'm also worried that the lower mid-range seems a bit echo-y and muddled. Some of this may just be my ears adjusting to the change in sound, though. The difference in midrange between the two 'phones was so noticeable I had to turn the volume down when switching to the regular TMAs.
To Care - James Blake
This song sounds pretty similar on both sets of headphones. The bass extension seems identical.
I Feel Better - Hot Chip
Bass at the beginning hits hard with both cans, but Studio seems a bit more echo-y and less clean to my ears. I suspect, however, this is just due to the more subdued mids on the Studios, which allow me to catch a few more of the details of the bass. I can definitely see how people are calling these guys veiled.
Holland, 1945 - Neutral Milk Hotel
Honestly the whole thing sounds muted with the studios. I feel a bit like the song is being played far away so only the bass is carrying over to me.
Holy Night Fever - Deerhoof
Much more forward-sounding on the regular TMA. Studio makes the repeated notes of the bass guitar overpowering and sacrifices a lot of the vocals.
You Ain't No DJ - Big Boi
The Studios sound pretty good on a song with spare production like this, but it's still clear that the vocals are too buried in the mix.
Crown on the Ground - Sleigh Bells
This song just doesn't really work on the Studios. It needs to hit really hard, but with these guys the joy of that guitar flying into the red is drowned out by the similarly blown-out but less exciting bass.
I really want to like these headphones, but right now I can't say that I do. I think I'll keep listening to them for the next few days to see if any of my feelings change. I guess I'll also try out the pleather pads, though I really want an earcup that sits around the ear like these do with the PU foam pads on.
Edit: Also, for anyone who may be interested, the PU foam (and presumably the pleather) earpads from the Studios will fit on the earcups of the regular TMAs. However, I found that the headband on the TMA-1 did not provide enough clamping force to get a good seal with the foam earpads. I'm now testing out the Studios with the pleather earpads, and I'll be sure to let you know if they change my opinions dramatically.