I received my pair of amps and a single power supply with the splitter and filter a couple of weeks ago, but just got the time to play around with them in the last week. I replaced an SMSL AO200 amp that I have been using with an SMSL SU-9 for a couple of years to drive my Wharfedale Linton's. It's been an enjoyable system that I have used a lot in my main listening room - very clean, but maybe just slightly lacking in power although I normally ran them at 60-70%.
Comparing the Fosi V3's, they seem just as clean and distortion free as the AO200 but a little more powerful and with
noticeably possibly, maybe, maybe not

better channel separation. I moved my subwoofer to a different location in the room and that improved the low end.
I mostly drive my system with a Windows laptop and Tidal, or Foobar2000 to play my collection of FLACs (or older MP3s). I am extremely happy with the sound and performance of my new setup with the Fosi's. I'm not going to try and discuss any subjective feelings about the sound, but these amps drive my speakers well and I feel like it is a worthwhile (if not dramatic) upgrade from the AO200.
Regarding the running temperature - I was surprised how hot these little buggers get when you really drive them - almost to the point of uncomfortable to the touch. I had a couple of AC Infinity USB powered fans laying around (these have been mentioned in other posts here) but I didn't want to put them under the amps, so I tried setting them on top, with the airflow going up, away from the amps. This made a huge difference in running temperature. I haven't measured it yet, but I would estimate they run 50% or more cooler with these fans drawing air away from the amps.
Great job Fosi with these amps!