I have one and love it.
AFD mode - fat, gainy, singing lead tones from the extra gain stage. Use the low input for a classic JCM800 tone (i.e. one gain stage less than the high input).
#34 mode - fecking bright! It's a bright(er) stock JCM800, so you need to crank it to get the best out of it. It's Slash tones from Use You Illusion onwards though, and great in a band mix. Not so good on its own at home unless you like it BRIGHT!!!