Absolute rubbish! Trust Kevlar and I. When I was 16, I traded a Risson head, which was a good Marshall copy from the 80's. As soon as I came home and turned on the Carvin head, I realized the cleans were good, but the gain sounded like wet cardboard.
I tried to sell it, but everyone who came by hated it. I showed it to one guy, and the amp started acting up. As soon as he drove away, I took the amp by it's power cord, spun it around over my head, and let it fly into a brick wall. Nowadays, I cringe when I see an X100B.