Performance wise, I never even tried 4K mode. I will always take 1080p60 over 2160p30 when given an option. That said, the DF report on it shows PS4 Pro running more like 40-50fps all the time, and I can personally confirm drops to 30 and even below when I'm running around as Moze abusing her grenadier build. DF also showed frequent drops to mid-20's and occasionally even lower when playing in 4K mode so I know I made the right choice. Moze builds would bring that to teens easy. That said, it doesn't really affect the gameplay much. The grenade Moze uses tracks targets on its own so shit dies no matter what.
And yes, the endgame is pretty busted. There's a bunch of different ways to break the game as bad or worse than the Conference Call + The Bee combo from BL2. Loot went from MAYBE slightly too abundant to stingy as fuck in the hotfix which I why I refuse to play online. There's about 120 legendaries in the game, probably 75% of which are complete garbage. Of the remaining, it's about half mediocre/decent stuff and half stuff that's part of super OP builds. On top of actually getting one of the few good items in the game to drop, you also have to get the correct prefix/stat rolls. Hex is a godtier grenade for example, but only if it has either MIRV or Recurring as its prefix, and then you need shock and at least one other element. The amount of loot that dropped originally (and still does offline) is like Diablo 3: there's a shitload of it but you leave the vast majority to just rot on the ground. Even more so here since Gearbox is so goddamn stingy when it comes to vault space. I pretty much only pick up Flakker, Butcher, Lyuda, maybe 3 or 4 others I can't remember the names of right now, about 3 shields and grenades, 2 class mods, and 1 artifact.
Thankfully I'm about done with all I care to do in the game and will ship it back to Gamefly before they release an actual patch that nerfs things further. Avoiding the hotfixes is simple enough, but trying to stop a PS4 from patching a game it wants to update is way too much of a pain in the ass. I would have liked to play it on PC since mine is brand new now, but Epic and Denuvo made that impossible. I wouldn't have been happy about paying $60 for the game anyway, but maybe I'll get it once it's on Steam and there's a cheap[er] 'complete' version (without Denuvo, or it's still a deal-breaker).
As for the story, I suppose it's subjective, but I don't like the antagonists at all compared to Jack in BL2. They are more irritating than menacing villains, and the resolution really isn't that satisfying in the end. The writing is vastly worse compared to BL2, and especially TftB (whose characters reappear here in flanderized form and without Troy Baker as Rhys). Without getting into massive spoilers, I was not pleased with their decision to mix dick & fart joke style humor with much darker writing. There was no fucking need at all for what happened after the first vault. I found side quests much more entertaining than the main story, with a few exceptions that just didn't land their jokes at all.