Well the only difference is the control scheme and maybe a bit better graphics but i did enjoy the wii version heaps more.Its the same content too if you have a wii it should be real cheap now(well considering RE5)but i can't talk cuz i'm pretty much a bum.If you don't have a wii i wouldn't buy it just for RE4.
I can see you have an xbox 360 considered RE5 yet(i haven't played it lol).