Just picked up my T2... WOW!
They sound absolutely incredible! The fit is perfect and they're so discrete! Isolation is also satisfactory (passed Sensaphonics Seal Test with flying colours!) and very adequate. The cable is flexible, thin, light and almost non-microphonic.
The highs are very articulated and everything is very detailed (enough detail for listening to string quartets). The mids are admittedly not as smooth as the E500, but more detailed. Overall the sound is warmer than that of my SR404 and the upper mids are richer. The bass is stronger but never ever boomy. If I were to be very picky, the sound is still leaning on the Shure side with hints of Etymotic detail and brightness. IMO you get the best of both worlds! So everything sounds perfect? No! They are miles better than the E500 with so much more treble detail and presence, but still sound slightly veiled compared to the Stax. I guess it's just an alternative sound signature. Overall, the SR404 is still the better headphone, but the T2 come pretty darn close. The purity and transparency of electrostatic sound is still unrivalled
The veil is in the mids which gives a slightly warmer sound. The highs are largely unaffected. I guess you could say the T2 sound quite alike the SR-003, but with a greater amount of treble, transparency and at the same time a richer sound.
Bottom line: if you can fork out 499 pounds (974USD) and the above sounds good to you, then you should seriously consider the ACS T2 as a very competitive alternative to the usual suspects (UE10Pro, ES2)
I'll probably do a more detailed review plus pictures if I can find time...