how did you OC the shader ? the MSI tool doesn't support shader in this instance. Rivatools are way too old - or did it work for you ?
at first i was using riva tuner but my overclocked settings were not saved everytime i restarded win7 ( i had to re-enter the settings everytime which was very annoying)
so, with latest driver + modedninf from laptopvideo2go (267.32) i was able to play starcraft 2 on extreme settings very smooth at 30-45 fps.
i just pumped up the shaders to 1500mhz instead of 1430 (and 1100 originally) and my temp remained the same (about 65-78C) no fans kicking in or anything. very happy with my gt330
unfortunately for me, i have no use with the ati 6750 because i cannot use the desired drivers i need to oc max.
but its been proven its a very good gpu (better than stock gt330, but maybe equal to an overclocked 330)
so yeah, keep it mind it depends what you prefer ati or nvidia. for me nvidia has been providing support drivers and power performance all along the product cycle life.
the best solution to keep up with gpus as i said earlier is with Vidock. but you need a 4.1 gen macbook pro to use it.
P.s : i dont use riva tuner anymore but the nvidia settings when you right click and select performance to play with clock settings. then you create a profile so that when system boot up ur settings remain.