Edit: Yes it changes game play, what kind of idiot can't understand that increasing power and performance will increase game play? If you add NOS to a car will ride faster? If you have 256mb of ram and you add another 256mb or even...
Dell Inspiron 9400:
Stock - 100core/658memory
Overclocked - 350core/856memory
Used coolbits to oc video card. this proved to increase Aquamark score from 57k to 68k, and a 3DMark06 score of 3,200.