I am really enjoying it so far. Some random thoughts:
The difficulty seems to have been scaled down a little from the Alpha, enemies are much less bullet spongy. Biggest example I noticed was the first wizard encounter took about 2 minutes to actually take out the wizard. This time it took about 30 seconds ones I cleared out his minions.
It also seems like they lowered how long it takes to fill up your "ult" meter. This is great because it felt like it took way to long in the alpha.
I still think the magnum is really lame to have as a primary; it would be much better suited as a sidearm. It just doesn't do enough damage for the amount of shots you get and the reload time is way too long.
Chest placement seems real weird. In borderlands you have chests everywhere; if you follow the main path you are almost always guaranteed to hit a few in a level. If you go off the path and look you are sure to find more. In this game it seems really scattered and inconsistent. I kind of stopped looking through rooms that I clear since you don't actively pick up loot and chests are so few and far between. I keep having this feeling in the back of my mind that I am missing stuff as I am progressing. Maybe I am just ruined by games like borderlands and diablo 3 where you are getting loot and opening chests pretty regularly.
I love the unique jumps between the 3 classes. Each class has such great maneuverability and in such different ways.