I just finished Redfall today on my Series X. I did a 100% run and completed all the main missions, side quests and all the safe house missions. I didn't do a 100% achievement run, as some of the achievements are missable and some are tied to co-op and a few would require a second play through. And while I enjoyed the game, I didn't like it enough to grind 100% on the achievements. Although because it's co-op and you can jump in in and out of another person's game, it wouldn't be too much of a grind to 100% the achievements.
Overall, I enjoyed myself and would give the game a 7/10. I'm not sure if it has been patched already, as we are two patches into the game, but most of the buggy/dead AI seems to happen at the begining of the game. The AI also becomes more aware and agro as the game goes on and by the end, you can be fighting multiple humans, multiple standard vampires and elite vampires all at the same time and it can get quite hectic. The second town on Redfall island seems more alive, as the various human and vampire factions are fighting each other all around you. Some of the graphical glitches, like the textures slowly loading in or never loading in seemed to go away after the second patch as well.
I thought the gunplay was solid and by the end, some of the higher level rare weapons are pretty cool. The movement is solid and it's easy to off-line and circle strafe, which is important for an FPS. The boss fights are hit and miss and some are better than others, which is a miss overall, as the bosses are really cool and the boss battles should be more epic. It was fun exploring Redfall and some of the locations are creepy and interesting to explore. The main character design and enemy designs are cool. All the friendly NPCs have freakishly big hands, to the point that it's almost comical and graphicly, they are on the ugly side. The story was solid and each hero has their own back story and motivations that is added into the main story, so that aspect is interesting.
My postmortem is after two patches and my expectations were low coming in because of the bad press, but in the end I feel like I didn't waste my time and I enjoyed my time in Redfall.