These sound really, really good...no doubt about that. With the tubes I found them warm and detailed and able to offer quick, clean dramatic shifts in dynamics with an impressive degree of realism that is only compromised by the limited scale of a speaker with drivers this size. Sound stage and image resolution are, as expected, excellent. Tone is clean and pure and this is most evident with piano, acoustic guitar and vocals. Top end is clean and well resolved with no hint of sharpness or edge. They maybe struggled a bit with music that is comprised of a lot of different sonic elements occurring all at once...especially if some of those elements were deliberately distorted...but that's also typical of small drivers. With the F5 they got a little thin (could be a power thing) but a bit more detailed and weren't as engaging. With both amps the reproduction of percussive content was very good with all the little tonal nuances inherent to cymbals and drums present. They weren't alarmingly tactile in the mid range, but sufficiently enough to be fun. All in all exactly as they are described over an over by those who have spent some time with them...extraordinarily capable for a speaker their size and difficult to criticize as long as expectations are reasonable.
I'll play around with positioning next but last night they were seven feet apart (center to center), about seven feet out into the room from the front wall (treated/diffuse and absorptive), about four feet from the side walls (treated/absorptive) and I sat about eight feet away from them and was positioned about five feet from the rear wall (treated/absorptive). I ran them without subs just long enough to hear what they could do with LF on their own and they sounded puny, because they are puny (can beat distributed bass or dipole bass with big, capable drivers, folks). With the u-frame subs and a high pass at 100 Hz the result was, well, as described above. A very satisfying listen and the best small speakers I've heard, but not the best I've heard, period (that would be an unreasonable expectation). Up there, though. They set an excellent standard for mid range and and high frequency reproduction that I'll be referencing as I begin my journey into DIY.