I owned one of these things and as Empathy stated up there it's one of the best practice amps. You won't be recording an album with it, so it's fine. The tone wasn't that bad btw, I've seen worse (and way more expenseive).
I've played on Cubes of several different sizes and they've all been excellent for practicing. I don't even use a stompbox for distortion in front of it because the highest drive setting actually sounds pretty good. Also the most durable little bugger you'll find. Go for it!