I finished the game on Veteran on the 360, and then played the wii version later. It is a piss poor excuse for a FPS game on the wii. I hate the controls, and there are way too many options to change them, who has the time to sit there and tweak everything one by one till you like it. The online is laggy as heck for me and im using a very fast internet connection.
If you do not have a real system (PS3/360) then its ok i guess, might be worth going online a few times just to shoot some people, but i would recommend the game highly on either of the HD systems before the wii one. Its a really good game too.