I think Taarabt can be a very good player as part of a decent team, I just don't think he's someone who's going to make a poor team any better, if that makes sense.
How motivated can you physically be though when you've played for the best team in Britain for 10 years, numerous Champions League games against the likes of Barca and Real, won a shit load of medals and now you're playing for Sunderland.