I wouldn't bother upgrading from a Core 2 Quad to an i5-750 or even an i7 to be honest, unless you've got some specific task with which the current CPU is struggling. I'm managing just fine with an E8400 dual-core and am holding off upgrading as long as possible.
With regards to HT, apparently some games actually suffer with it enabled.
With regards to HT, apparently some games actually suffer with it enabled.


