So what you're saying is that it is thought to be unfair that someone with a faster PC running an optimised client shouldn't be allowed to claim extra credit, despite the fact that they are already doing more work.

At DC projects like WCG for instance any PC running 24/7 can achieve 960 points per day regardless of the throughput. If this is the case we would all be better to just buy old slow cheap rigs and do very little work while picking up loads of points. Kinda defeats the aim of getting the work done. Or am I still reading this situation wrong?