I got a late 08 macbook pro off of ebay- it is currently running snow leopard on it. I don't know if I should upgrade to lion yet (which I have a copy of...), but lion seems to give many people a drop in performance. I want to do a clean install, just in case the last owner left some malware **** on it, and have a lion bootable USB made. Should I go this way? I also have a leopard install disc and a SL upgrade disc (NOT an install disc). What would be the best OS to go for for performance, etc. I dont really use many of the features in lion, and if snow leopard is the way to go, I might as well just spend the time getting me there. I will be upgrading to 8gb of RAM too, as well as a 1tb HDD soon (within the next two weeks, if all goes well), so should I do a clean install when I switch HDDs?