You should definitely try a Katana if you get the chance. They really are quite outstanding, if somewhat more expensive than most of the competition, especially when you add in the cost of the GA-FC which you ideally need to get the most out of it. Thomann have currently got one of the 100 1x12s as B stock, so you could always buy it and then send it back . . although that is rather naughty. No-one seems to have any new 100 1x12s, they're always on 'pre-order' or 'due back in stock on . . ' so getting that one from Thomann might be the only way to test one.
The only annoying thing about the Katana is that it is very firmly mono. I have been running the stereo out from my Zoom pedal - one side into the Katana, one into the Mustang - just for the craic - sounds lovely!