where you will see an improvement is. by increasing your res. over your current one.  you will gain fps ( not much ) but your also increasing your res.  another note. get a refresh program. Unless your using one now. your MOH game defaults back down to 60Hz even though your desktop may be running much higher then that. 
Check out :
http://www.guru3d.com/files/
for the refresh fix and other tweaks along with all the latest drivers.
good luck