Most of the active systems I have heard/used have been for the pro market. So the likely hood of using a Tube amp in them is zero. Amp technology has come along way since the bad old days so I think the idea that because it is active means it has less than great amps is probably old now.
All the characteristics can be worked around to make the design work in most situations. You just have know what you are chasing.
The Genelec monitors I have used in studios over the years have always been "nice" sounding, but I have always found them hopeless to mix on. They sound great and musical with that flabby mid bass which gets in the way when you really need to know what is happening in the mix. I feel the same way with the Mackie monitors too (last generation Mackies). They sound great and musical, but take the mix somewhere else and it sounds flat. I do like the ATCs as they seem to have less of the color of the Genelec but still musical and detailed.
I have yet to find a great powered monitor for the studio although I do like the Adam active monitors. Being an Apogee and planar fan, I guess the Adam ribbon tweeter had the detail I crave to an extent.
I have never heard a modern Field Coil speaker, but I see Focal are making one which I am told is good although expensive. I believe the idea is to bring the design to the lower range soon.
I recently bought Avantgarde Trios for my Hifi. A 110db/watt hornloaded speaker with active sub bass after years of various planar speakers. Many of the traits I thought were the domain of the Planar/electrostatic were easily achieved by the Trio, but with the dynamic swing no planar I know is capable of. I am sure if I used Avantgardes own amp design for the passive part of the trio, essentially making it all "active" you would never be able to say active speakers are not or cannot be SOTA.
