Although I haven't done a review on this character yet, I'm doing it now. This is one of the best Sonic I've ever played with in this game, and I'd venture to say that he's one of the most brightest and well-made Sonic I've seen so far, and he's also the most faithful to what he really was supposed to be, and I also thought it was cool to reuse bugs from Adventure itself, like Super Bounce, which is already quite abusive for speedruns.
And now about Rush Mode, I've never been such a fan of Sonic Rush so I can't say much, but I can say that this is the biggest and true Sonic Rush experience for SRB2, the work these folks did in weeks was incredible!