I seem to have noticed, that the wii in particular, that the whammy bar breaks. I know several people that have the wii version and its whammy has snapped. If you want to fix it, Simply use a rubber band and wrap it around the whammy and the guitar strap. Simple as that. :3
I have the PS2 version, Which bar load times is exactly the same as the wii. The PS3 and 360 versions differ only in Downloadable content.