I'm slowly working on Borderlands 3 with my wife. I've also been playing through 2 again solo at the same time, so I've been able to directly compare. Haven't done much solo yet, and I like to play both so I can play multiple characters/play styles as well as take in the lore at a slower pace by myself. That being said, I've enjoyed what I've seen so far in my maybe 10-15 hours of game play. There's a ton of little quality of life and graphical additions that are fun for fans of the previous games. Ammo, money and Eridium now all pick up automatically. Going back to 2 sucks for that feature alone. The weapons seem more varied and there less of the "exact same gun but does different damage or has a different capacity so it's technically different"The weapons have a wider array of zoom, and bullet types. Many also have secondary modes, like grenade launcher attachments, or burst/auto selectors, or 2 elementals that you can switch between. I find myself changing guns out frequently just so I can try them all. Damage between them seems more balanced, I haven't found anything that feels super over powered. Enemies move more fluidly, so I find that spray and pray works better than sniping now. The enemies re-spawn really fast too, so there's almost always something to shoot just a short run away.
I don't have a ton of complaints so far. I think my biggest one is the menus are pretty laggy, and the sensitivity seems to be off. I'm playing on Xbox One, and have it fully maxed, and it doesn't feel like enough. I liken it to the controls of Halo 3, which also felt like I couldn't turn or look fast enough some times at max sensitivity. The other complaint is that the new major enemies aren't as compelling as Jack. With a few exceptions that I won't spoil, my main motivation to defeat them has been because they're annoying and in my way, not because they're constantly messing with me and the characters I played (the Mordecai bit in 2 killed me the first time), and nothing they've done thus far screams, "wow, that was some truly evil shit" like Jack did in 2. I'm hoping it comes later, and now that I think about it, they really ramped up Jack's villainy in the second half of the game.