I was able to convince a buddy of mine to let me "borrow" his Steam account so I could try the game out.
It's an OK game, but my worries of it being a console port have definitely been confirmed. Runs like shit on my 4870 and i7 920 @ 3.6Ghz. Mouse movement is very jerky... the smoothing is HORRIBLE. Trying to snipe from afar is a joke. FOV is, what, 50 degrees? Can only bind 1 key to any action.
You can fix the mouse smoothing and the fov (although the fov fix isn't permanent). Runs fine on my rig in my sig. Also, I don't know what level you were, but the game gets better as you progress and get better weapons.
That said, the game is missing a lot of things that make it perfect:
Lack of minimap
Crappy map
Piss poor menus
Lack of autorun button
lack of a healing hotkey
lack of usable skills
Hopefully most of that stuff will be added if there's ever a borderlands 2 (i gave up hoping for this stuff in a patch).
that said, it's still a good game if you don't mind some of the mmo-like quest structure. You'll put a lot of time into this game if you're interested in playing as all the characters in some fashion or another.
Definitely worth $10 if you're even remotely interested.