I auditioned them once for about 3 hours with a Musical Fidelity A5 and matching CD player. I have auditioned many speakers and these are by far my favorite speakers.
They have an extremely wide sound stage (because of flat drivers?) with pin point imaging. They are also one of the most tonally balanced speakers I have heard. The bass was never over done and always had good punch and depth. But best thing about these speakers though is how well they integrate. The drivers are seamless. I always thought a lot of speakers had good diver integration until I heard these... they are on another level.
Many people say thiels are bright. The 3.7 are not bright at all, it is balanced. They are VERY detailed and many people might perceive this as bright. They made the Wilson audio Duettes (same room same amp A/B comparison) sound un-detailed and boomy.
Anyway long story short I really like them. They do not get the press they should around there. It would be worth the trip to hear these speaker if you are looking in their price range (13,000). But in truth I think you will find they out play many speakers costing much more.
PS. The 3.7 will be my next purchase. I was looking into a pair of Sophias. I heard the Duettes side by side with the 3.7s and the thiels were better in all aspects. I made the 2 hour trip anyway to hear a pair of Sophias (different dealer, Mac gear) I still liked the Thiels much better. To me the 3.7s are more detailed, have better driver integration and the bass seems more natural (IMO of corse). Use your own ears! Sound stage was close with the thiel still coming out on top. I think I would have to move up the Wilson line to compete. But for the price of the Watt Puppy I could buy the 3.7 and some killer amps for them.