You're still wrong...WB5 has no performance hit, the only "hit" is when it's applying a new skin which can take10-15 seconds but after that everything is fine, memory? the main program isn't even running in the BG to use memory...
I used to have WB5 but the transparent borders on many skins whilst nice were more distracting on programs that don't suit such borders so I just use a plain visual style instead. WB5 was faster and everyopne that has used it agrees.