The Wii one also has the better OM NOM NOM Wisp. Void is cool but controls absolutely horribly.
The Void wisp may well be my favorite one in the franchise. One you figure out how to control the thing (the key is not to oversteer sections, then it handles like a dream) it really is a novel way to blow through shortcuts. Its like the hover wisp on steroids. There is actually one section in Asteroid Coaster where
Coming off of the Frenzy wisp, I'd dare say that the Void is an improvement.
Comparing the two versions.... I don't know. The DS version certainly plays like Rush, but it is not. The lack of a trick system really makes you depend on wisps a bit more and that makes boost a little bit harder to come by. Even that slight reduction in tension gauge has a big impact on gameplay, making wisp usage the key. Its, Rush 3, but then it isnt. Colors Wii brings solid platforming back to the series, and is pure eye candy.
By comparison standards alone, Colors DS doesn't recapture the magic of the original Rush (which is both good and bad). Colors Wii outshines recent endeavors on the consoles, so I think that one gets the nod.