They don't sound bad at all - they just constantly are run with too much gain, because it's a common choice for beginners as a "my first tube amp." If you run them at grownup settings on the dial they are good sounding amps.
IMO the weakest link is the speakers the combos come with stock. Those are garbage. They really need a v30 or T75 to sound "right."
I also disagree that it sounds better than a JCM2000. For all their faults, bias drift, etc, the JCM2000 DSLs have more natural sounding, organic sounding gain IMO. I would take a JCM2k and a decent overdrive over a new DSL 100/100 times.