Thanks for that info Mana Knight! That's saved me $20. Hard and cheap is exactly what I hate about Sonic Rush (and Advance 2, and the 3D games), so if it's even worse than Rush, I know I'll hate it.
Rush left a great first impression on me-I was cranking up the music, and blown away by the graphics, etc.-but within a few levels I was stuck, dying from blind jumps, etc. IMO Sonic games should be on the easy side if anything, and shouldn't ever make you slow down and be cautious, which is exactly what most of them do. (At least that's what I want from them.)