I'm one of the beta testers of Little Big Planet Karting. And it's not exactly what I expected. The only thing that ruins it is the handling. It is not the same as in Modnation Racers, it feels very uncomfortable, you should improve it, is very difficult to bend and you do not feel as free as in ModNation Racers.
The handling totally ruins the whole game, and it's not fair that a so promising game be ruined because of one basic factor.