Re: Speed, Components and Bottlenecking.
It all depends on what you're doing. In terms of anything "bottlenecking" your system, it does seem like the weakest link would be the i5. At the same time, however, I don't see many mainstream situations where your GPU, RAM, and HDs would be maxed out to their full potential, and where the i5 would be struggling.
I don't think you should upgrade anything at this time. If you really feel like the i5 is the problem, try overclocking it a bit. Back in the day, my Q6600 wasn't the fastest processor on the market, but I sure didn't consider it a bottleneck compared to my RAM/HD at the time.
Intel Q6600 @ 3204Mhz ~ Tuniq Tower 120 ~Corsair XMS2 5GB ~ WD VelociRaptor 150GB Main ~ WD 1TB Black ~ EVGA 8800GTS 640MB ~ 7 Home Premium (64-Bit)