I'm sure some here have/had both and will have more info, but I intensely shopped both of these when making my purchase a while back and am beyond satisfied with my T-Verb choice.
Both are great amps with lots of flexibility...but for me....the T-Verb is WAY easier to dial up great tones fast. Much like the Mark series...the Roadster seemed to have too many variables between my wants and what comes out of the speakers.
Both can achieve most anything you'll need....but in situations where the venue, P.A., bass tones, the weather...or whatever...has us guitarists tweaking a bit to suit the situation...I choose to enjoy the T-Verbs simpler & quicker interface to master the moment. (& maybe I'm crazy...but it just seems to have more automatic mojo)