As I’ve mentioned before in this thread: My Conrad Johnson Premier 12 tube monoblocks, 140W/side, drove the 3.7s beautifully. It seemed like an "ultimate" combination of lush, organic sound, but with precision and plenty of power.
A friend who is a high end audio reviewer, and who actually wasn’t fond of Thiel speakers (felt they were always too bright when heard at shows/stores etc) was simply blown away by the combo. He felt "it just doesn’t get much better than that."