I have Ayon Crossfire since 2010 when I changed my speakers from JM Lab Electra 1037 be to Duo Omega G2.
I owned all 3 iterations of Crossfire , IMO it's close to perfection match with AG speakers.
I tried many ss and valve designs and I am of the the opinion that AG sounds best with SET amplification.
Crossfire gives no typical valve sound - it's fast ,dynamic with holographic sound stage and very colorful bass.
The bass is of course a bit less controlled than with ss amps ( like XA series from AG ) but with much more colours and saturation. Compared to that, ss designs produce better controlled deep bass but it is washed to me.
And it has punch and power - plays louder than 100 -150 W ss designs, as loud as for example ARC ref 150 power amp , as far as I remember. Cons ? With efficient speakers it's always a little bit of hum , when you approach the ear to mid horn is audible. Here XA pre/power combo from AG has the edge.