I'm 99% all premium accounts with rapidshare,megaupload etc DON'T make you upload faster. They do let you download quicker (well a few of them anyway) The main reason in premium accounts with any of these is so u can download more than 1 set at a time & avoid all the advertising/waiting times.
I've found the quickest site to upload to is mediafire (lets me upload a whole pack in like a hour & a half) wich is fucking gd compared to most of the others. Otherwise use shareonall (you upload the file you want to there and choose what others sites u want links 2 u file from ie. rapidshare,megaupload,sendspace etc.