[anandk]

no pack, per say, slows down a system, noticebly ! It actually modifies the current .dll files like uxtheme.dll,shell32,dll etc. but it won't take much of your memory to do so. But the other utilities like Dock Y'z shadow Y'z toolbar uses some random memory...the choice to addtitionally install these rocketdock, uber icon, yzshadow, yz toolbar r optional.