I didn't have any problems with my copy (as in the box I purchased from a store) of Oblivion, the copy protection was pretty transparent, and I didn't notice any CD-check lag while I was playing unlike Morrowind. And the no-DVD .exe from gamecopyworld saved me from the rigors of having to reach for the disc everytime I wanted to play.
(unfortunately Google, being dorks, have made it so the search function on gamecopyworld doesn't work, in the false believe that gamecopyworld provides any service to pirates whatsoever; in fact it doesn't, because pirates always get a no-dvd patch in the .zip or whatever, they don't need gamecopyworld whatsoever. So, you'll have to kind of manually search to find the .exe most likely)
