I have 380 toob watts, and it's enough, but I could always use more. I have also powered them with a 150 watt Threshold amp. Was ok, but the toobs bring them to life. Me thinks, perhaps the extra watts are responsible.
With Maggie 3.5's, I had very good results at medium output levels with an ARC VT130 which was 110w....midrange bloom was spectacular and when the amp clipped, it was soft. A change to a 400w Counterpoint hybrid amp helped some in loudness and a great tonal coherency too, but it took away some of the magic of the all tube amp. I then changed to the Wolcotts which gave me a good balance of both worlds.
No matter how much I tried to throw at the Maggies, dynamics was simply a limiting factor. They do so many things incredibly well but I felt I had to play the music louder than I should have simply to get the music out of the speakers. A change to Sound-Lab and now I have all the Maggie magic and far more low-end extension, clearly more low-level detail in the mids and highs, wide sweet spot and significantly more dynamics so I don't have to blast the music. The SL's are very happy with medium output amplifiers.
The Maggies are one heck of a bargain speaker, but you have to pay a lot to get an amp to bring out there best. And from what I have read on many threads here, so many Maggie 3.x owners have not even come close to hearing their potential. Bryston amps just don't do it at all no matter how much power they may have.
I agree with Jafox, the Maggies are great but you need very good amplification to drive them. I finally gave up on my 1.6s after using Innersound ESL amp, Plinius SA100 MKIII, Plinius 8200 integrated and Rogue 120 monoblocks. The Rogues were the only tube amps and at 120 watts sounded nice but no dynamic range. I finally gave up and now have low powered tubes and high effeciency speakers.