Yes they work with steam version. It is exactly same version as retail and uses same files. (except launcher) It also have same activation. The only different is, that you don't need DVD with steam version.
Yes the latest trainer works very well with the game on steam and yes steam games has it's advantages as well it's down side on havin it also but that is another subject to discuss somewhere else than here
ok this trainer seemed to not trip off Games 4 windows live, but the car damage cheat Doesnt work.. But overall I give the trainer a 4.5 because it gave me the one man army and walk free achievement.. :-) So, once the car damage is fixed I will give it 5 stars!!