I uninstalled mine today actually, these are great graphical upgrades no doubt, but the problem with all these add-ons is that it's putting more weight on top of a very unstable buggy game that's already dragging ass from the start.
So basically, the more Gearbox adds to it, the more fps loss or overall taxing on your PC rig you'll experience. Before all the updates the game was running quite well, even in heavy action. But now, with all these new lighting effects, texture upgrades and SSAO options ect, it's just doing more harm than good. I've seen this before even with Crysis 2, the more they kept on updating the graphics the more players started complaining about fps drops.
If of course you don't mind stuttering and 20-30fps dips to your gameplay in heavy xeno action, knock yourself out.