With the caveat that I’m not the most experienced player and certainly not at loud volumes, I have one and think it’s great. I’ve been through a few different home setups including Genzler Magellan 350 “combo”, TE Elf + 208/Barefaced One10, PJB BG-75, Yamaha THR30ii, Ashdown RM800 and an Orange LBT.
I wanted something for home that would be silent (I loved the Elf but the fan noise drove me nuts) and cover everything without the need for pedals - comp, drive, effects, bluetooth playback from my phone/ipad - the only thing it’s missing is a tuner. I’ve recently started playing in some rehearsal spaces where we can turn up a bit, we were hitting 110db and master wasn’t at half way. Certainly more power/volume than I’d ever need.
To my ears it sounds brilliant.
The only thing that lets it down is how bloody heavy it is, I wouldn’t want to be lugging it around very far. So much so that I’m considering something lighter to take to rehearsals such as Rumble or Ampeg combo with a preamp/multieffects as needed. But I wouldn’t need both so the Katana would probably go - a shame!