I played for about 5 hours today, probably at least 8-10 runs, none fully successful (though we got to the first Nightlord once). Haven't explored all characters yet since I wanted to get used to their skills. Here are my thoughts:
Map & movement
I like the map structure and the quicker movement, though I'd expected more randomization regarding the map layout. There's apparently still some bigger map events I haven't seen, but it feels like things will get fairly samey quickly.
Combat & teamplay
I'm surprised how good this felt! Haven't really played co-op Elden Ring, but the boss fights genuinely get my adrenaline pumping & make me root for my teammates. Things feel a good bit harder than in Elden Ring (since you're much lower level & it's scaled for 3 players), and I hope they adjust the balancing a bit, but it's what I wanted: more combat focus & quicker rounds.
Lore & story
Haven't found much so far, but the Nightfarers are done well and feel like unique characters. I just unlocked the Duchess, but I'm still missing the Revenant (though I have an idea how to unlock her). Feels like there's a bit less lore stuff than I'd hoped for, but there are already some nuggets that improve my understanding of the main game :)
Overall feelings
I'd give the game a 7 or 8 / 10 so far. Not as enthralling as Elden Ring due to the missing meta progression, but it definitely scratches that "one more round" itch. I'm looking forward to playing more over the next couple of days!