Played it recently myself, with the CP 1.74.
Run absolutely smoothly, in my modern rig. Not a single stutter, except the classic one when drawing a new flame source (torch/fire arrow) on a just loaded game. Perhaps the SSD helps.
Only one bug, with creatures sometimes clipping into the terrain. Prevented me from finishing one quest in Nordmar, because one deer I had to hunt clipped and got stuck in a mountainside, I saved before I noticed, and the previous good save was hours ago.
I used alternative AI, but not balancing, as I like to end up as an ubergod that can rape anything in any matter of his choosing, and I definitely was one near the end of G3 (finished as a Lvl81 Paladin, but really, there was nothing I hadn't mastered/couldn't use by that point).
Played most of the game as an archer, which seemed really overpowered, being able to kite even the most fearsome creatures at very low levels. Killed my first dragon at level 12 or so (one of the two or three at the bottom of the Cape Dun caves), took about 50 arrows. Packs of low-level creatures (wolfs, snappers) were much more difficult to deal with than lone powerful beasts (shadowbeasts, monsters, trolls).
I only started developing melee skills after lvl60, and I had the Paladin armor, which reduced the amount of damage you take so much, you might as well have cheated a god mode on. I understand that Alternative balance changes the way armor works too, so maybe the Paladin Armor isn't so ridiculously effective.
I didn't much like the desert area, and I found the excavation sites/ruins near Mora Sul very hard to navigate without getting lost, the only place in the game I had this problem.
I liked the great potential for exploration and the lack of handholding.
Also, someone said the game takes 40 hours to complete. Perhaps, if you are in a hurry and are trying to finish asap, but a thourough playthrough, completing most quests, exploring all the terrain and so on will definitely take more than a hundred hours.
On topic and in case it isn't clear, I think it is more than worth $5.