I've been using xMule for a while, and it took me ALL my bandwith even if there were no active uploads/downloads, so i coulnd't even browse the net.
Another disappointing thing was that xmule wasn't looking all the time for sources, only in 2-3 files...all the others were in red, disappointing....
I don't recommend you xmule, for my very bad experience, but i think (hope) others will have a great performance.