I saw the tv show where he actively petitioned to be in the new film (it was Chris Evans's TGI Friday if you're interested). He said he'd be a stormtrooper, anything just to be in the film.

And he certainly enjoyed it enough to want to be in the new films, however improbable that might be (if he were to play the same character, of course).

I thought he was a good addition, personally. I liked the animosity between him and Anakin in the first film and the fact that he got stuck into the action in the second one. His death scene was outstanding in the third film. What's not to like?