Didnt play abyss, so cant comment on that. Got several essence but afraid to use them ... yet.
I forgot to mention about improvement on the map system with blue tint to represent area you already explored, icon that appear when you reached certain distance from important target (door, shrine, abyss, special beast etc). Simple but good QoL improvement.
How I could forget about improvement for frame lock. Im probably one of the person that doesnt mind about quality of graphic as long as it is smooth. Sometimes despite lowering graphic setting, POE tend to lag allow with weather effect (in act 1 town or act 3 garden). Finally manage to experience another game with this feature (the first one i experienced was in The Witness)
Another feature I forgot to mentioned was the ability to see stat ranges when you press alt on any item. Although Tier stuff is still confusion at least I know that now if I find a lot of Tier 1 stuff that fit my build, it is definitely good stuff. I always have that problem in many arpg game.
Skimmed through Kaom then until Malachai for act 4 clearance. Reached act 5, overall my impression is the map is feel kinda big for some reason, remind of 2nd level on the way to piety. Again, as my usual reckless gameplay I though I could just survive with 50% resist in act 5, turn out it wasnt enough for the big boss (forgot the name). Boss fight is nice with tons of bullet-hellish projeciles, really remind me of boss fight in Furi. But turn out, even with my powerful recently found 4-link multstrike techno..i forgot the skill name is still slow against big boss like this.Died couple of times because of the projectile. (1.4k hp, around 50~% lightning resist, assuming that the boss element).
Another extra QoL stuff that was added that I didnt noticed is now your master will teleport to you whenever you done your task (Vorici + Tora) which save some little time instead of walking back to them.