I unfortunately haven't been able to test Amphions. But I did test PSI A21, Barefoots, Genelecs, Focals and ATCs.
Genelec's latest offerings 8260 and 8351 were speakers that blew me away like no other. Their midrange was the most natural and their soundstage and their clarity was above others I tested - I guess it is related to their coaxial mid/high drivers. Spaces and reverb tails on Genelecs are the most expansive therefore they provide the best front to back depth. They also are very detailed, but never fatiguing. They are open but smooth and very easy to learn...
I also want to say that I preferred them to the others mentioned before calibration...but after Autocal calibration...they literally became one with the space. So I really want you to know that GLM and DSP speakers are not marketing gimmick. They really do work, to make superb speakers simply unbelievable. Of course it won't turn bad sounding room into perfection...but it will make it more than usable. But calibration in a good sounding room will bring the speakers to perfection.
I know there is lots of unexplained Genelec hatred here at Gearslutz and Genelecs never receive hype like other brandss for example....but they really don't it. When I A/Bed 8351 agains SM9 I couldn't believe these two products are similarly priced. Focals were a coloured phased mess compared to 8351. It became so obvious which company invests into R&D and which into marketing
I like ATCs larger speakers (50s and on...I haven't heard 45s though). Had 25s and 20s and sold both few years ago. They are also specific sounding speakers, not so flat, more midrange forward, but I find them slightly boring to work with. Besides I never understood their low end, which sounds so different from what I am used to hear.
My impression after trying Barefoots mm27 Gen2 was that they are nice bouncy tracking speaker. Best I could describe them in one sentence is that they are slightly artificially detailed but lack real resolution. Low end, while really powerful, seemed slightly misleading to me. Their imaging is ok, but nothing to write home about.
PSI have a very analytical sound signature. They sound more like speaker and less like music IMHO. They are also very clear but I couldn't understand them easily. I would very easily miss the overall balance if I was mixing with them, so I suppose I would need really long learning period.