TLDR: Did you like Borderlands 1 and 2? You'll love Borderlands 3.
Having played every iteration and DLC of Borderlands 1 and 2, so far we are off with a bang.
Everything feels smoother. Movement, gunplay, driving, management, and so on. The art style is still here, with obvious visual upgrades and animation that enhances the original look
Massive quality of life changes, such as not having to manually pick up cash, health, or ammo, as it's automatic, streamlines the game.
The ability to grab ledges and pull yourself up makes climbing and jumping feel more natural and not hit or miss like it used to.
Tooltips are clean and easy to read, with the ability to easily compare equipment efficiently.
The map is a 3D, scaling, rotating render that takes a lot of guess work out of pathing and getting to your destination (much like Doom 2016).
Quest markers now tell you if your objective is above or below you.
A built in ping system (similar to Apex Legends) let you quickly identify and highlight destinations, items, specific enemies, and so on quickly. Just look at it and ping it.
You can fast travel to any fast travel station from anywhere on your map that you've been to, taking a lot of unneccessary legwork out. Your vehicle blew up? Fast travel and get another one. Even better, you can even teleport to your vehicle!
Co-op is curved to the individual. No more joining a high level game and getting murdered by high level mobs, or weapon drops you can't use. Monsters and loot are matched and curved to everyone. A level 8 could play with a level 33 with no detriment to both.
The playable characters are dramatically different in playstyle, and each contribute interesting combinations of skill sets that compliment each other.
There's more, but if you liked Borderlands 1 and 2, you will love this game.
It's too early to tell if the story is good, or the endgame is good, but with 6 hours played so far, I was blown away.
Update 9/18:
Playing strictly on a great PC, I haven't encountered any serious issues with the game. There have been a couple of odd things that have briefly happened, and possible bugs, but nothing game changing or game breaking.
I understand that console players main issue is the split screen performance and frame rate problems. Hopefully that will be resolved for you guys.
The ONLY issue I've personally had, and it's more of a gripe than a serious problem, is quest NPC pathing is a little dodgy.
I've played quite a bit more of the game, and another great feature is finding the secret challenges. Should you travel close to many of them, they will appear on your map waiting for you to claim them. So even if you may have blown past an area in the heat of vehicle travel or a fight, it will let you know it's there.
The story has progressed quite a bit for me, and I'm still loving the expected combination of seriousness and humor from the story. Seeing the 1st and now 2nd vault hunters from another perspective is fun to watch.
The fights have quickly become more dynamic. I've found myself having to use more strategy than just planting behind cover and pressing fire. Movement has become a bigger part of the game. I wasn't sure why the slide mechanic was introduced at first, but I definitely know now.
My review still stands. Great game.