Auditioned many integrateds including the 3 the OP is asking about, bought the 300, to my ears the best of the lot.
Here is my informal ranking of the integrateds:
Gryphon 300
Accuphase E-5000
Aesthetix Mimas
Mcintosh MA12000
Hegel 590 <-> Gryphon 120
Luxman 509
NAD M33
My system:
B&W 804 D4s
Lumin P1 streamer/DAC
Lampizator Baltic V4 DAC
Linn LP12 Selekt TT
Primaluna EVO 100 phono stage
Transparent and Audioquest cabling
Puritan power conditioner and ground system
The Accuphase I suspect for most ears is as good as the Gryphon, just not to my ears for my musical tastes which run the gamut from ambient electronica to jazz to chamber music to classic rock etc. Those with less broad musical tastes - vocals and acoustic instruments for example - might even prefer the Accuphase for its more refined tone/timbre. The gap between the 300 and the Accuphase and the rest of the amps on the list is large IMHO.