One issue that bugs me with x-box controllers is that they work in the same method as the arrow keys: Instead of the ability to move around quickly (and inbetween 'nodes') as with a mouse, you're limited on where you can go. This is even game-breaking if you try to use the 4-lane tag. I tried to get around this by using JoyToKey to bind the mouse to the x-box controller's sticks, but since Audiosurf detects the x-box controller, it's no use.
What I think would be nice would be an option to either disable Audiosurf detecting a plugged in controller, and/or let players choose how to bind the x-box controller (Perhaps also add the option to make it control the mouse cursor/mouse buttons so that someone can navigate the menus with a controller only)