Been hearing pretty good things about forces. And while everyone made the easy jokes about custom characters, the gameplay variety the feature provides is very appealing.
But let's be real, the more consistent and seasoned developer here is the Mario team. Sonic team can be very technically skilled, with Colors, Generations, Lost World, and Forces looking fantastic. But even their best efforts fall short of the likes of Galaxy or even 3D World. They just aren't consistent and can rush things, resulting in an unfinished feeling (looking at you Generations). I think Forces will be good. But the franchise has a major uphill battle to get another shot at being Mario's true rival.