It's bad.
The gameplay is fun for a few hours, but that's seriously the only part of the package that's any good at all, at least on the PC. The menus on the PC version are fucked (left/right facing arrows have identical functions, not opposite ones, scroll wheel only works in some menus, some you have to use arrow keys or P-UP/P-DOWN, and the menus are worse than unoptimized; I think they were actually made to be as laggy as possible... looking at my inventory actually lags more than looking at the horizon, with all the mountains and NPCs and such), it has random lag spikes, they pretty much botched lower-resolution settings (playing on 640x480 like I want to means that instead of an outline on everything to make it look cartoony, I get black pictures with color spots in the middle, basically), and it requires that you install it in an acceptable location to function properly (my setup, I have one HD for operating systems, and another for all my stuff, like music, games, videos, and I installed Borderlands on the other HD, turns out that just won't fly, and I have to install it in the same place as Windows, and I don't have enough room on my Windows partition for a whole modern video game, since all my free space is on my secondary HD, dumbass developers). All after Gearbox said that PC was their primary platform.
And from what I hear, getting it to work online is some sort of shitfest.
Yeah, I'm not buying any more games from these people after this. They said PC would be the best platform (and I'm a PC gamer exclusively), then made the PC version the worst version they released. And it was BAD. Fifty bucks gone, and it's not happening again.