I need some convincing - and fast (got an offer to buy the game for really cheap, have to make my decision ASAP). Got some questions:
1. Is the campaign worthwhile? Any cool encounters or boss fights?
2. How long is the campaign?
I have a really good group of people to play MP with, I'm just concerned about lack of time due to work. Would appreciate a quick answer if possible. Thank you!
Campaign is 16 missions, they're all pretty decent. They are all much better when played co-op.
You'll need to be careful to stay within a couple levels of your friends as you progress through the game. The game will adjust the levels of the bad guys upwards when a higher-level player joins your party, and once a bad guy is about four levels above you he'll feel untouchable.
I think you can casually do levels 1-30 in about 30 hours, and that includes running all the missions, the side missions, and enough encounters to unlock your base 100%.