I suppose it may be that different computer hardware sees different levels of improvement. Clearly Supreme0verlord's AMD gets more benefit than my Intel for example. But even if I don't see an improvement in PPD, WCG benefits from more WU's being done.
At the expense of maybe sounding contradictory to my previous post: wether it is an increase of PPD or just more completed WU's Linux certainly presents some benefits over Windows. Not least the fact that if you have more than 1 computer crunching you don't need to keep buying licenses for each one.
I suppose if more people who've tried this show their results Supreme0verloard (or myself if he doesn't want to) could compile a small chart/pro-con list for anyone new to this thread seeking information