Straight up is a fair trade. Seriously, people do it all the time. It adds a little bit of downforce but not nearly as much as it adds drag. And it has weight. No, taking it off is a serious performance mod.
Maybe money would change hands if one is debadged and the other is not. Otherwise I think they're even.
Also, make sure you change the springs. Oh, and of course you'll loose the ability to open the trunk with the key
