I have played the whole game and I like it a lot and so does my son, who was addicted lately to some other game but now he can't stop playing this one.
I also want to compliment Gearbox on the technical quality. We have this game both running on XP and Vista 64 bit and we have not encountered a single crash, bug or slowdown, everything works 100%.
I just wanted to share this, after reading so many negative posts on this forum.
The game should not be approached as a clone of call of Duty and you really need to run it on descent hardware. Me and my son run it on a 8800GT/GTS with double slot cooling, and a core2duo and core2quad with 4 and 8GB of memory and the game runs as smooth as silk. Run it on less and you get what you pay for, sorry.