I waited two whole years after this games release to play it, so my opinion is well divorced from any zeitgeist surrounding the game. I also played it all alone, singular, nobody else to play it with. I would have played it with my brother but PC games have apparently yet to get a handle on local coop, so that was out. I don't say this as a detriment to the game, but to frame my experience with it.
This is a pretty fun game if you look past the silly nature of the story, and the wacky writing, which is precisely what I did. I turned on a few podcasts to accompany my time vault hunting, so most details on what was going on outside of micromanaging guns and shooting robots in the face has been lost on me, and that is how I like my Borderlands. This style of play did bring something interesting to my attention, you can see the story of Borderlands unfold pretty well through a purely visual nature. What I understood is that Handsome Jack is an asshole, the old characters of Borderlands show up to form a resistance, some people die, you fight robot uprisings and fight a big bad at the end.
If you enjoyed Borderlands 1, this is just more of that on a visceral level. On an intellectual level, Borderlands should not be talked about, because I don't think it cares much about how it appears intellectually, which is fine, at least it knows what it is and who their audience is. Which brings me to my biggest problem with the games, referential humor. There's a lot of dorky references that are handled poorly and most just serve as a name drop, which I always fail to find the humor in. It's like having an out of touch dad come up to you and say "Here's this thing you might recognize! See, I know what it is, I'm hip with it right dawg?" A conversation that's started that way, will end that way, and that means going nowhere.
So yeah, 4/5.