Coming from a dude that played a good part of the TES series, and TW 1+2 I really fucking enjoy the third one.
The storyline....most questlines (baron for instance) can be summarized by everything going to shit and you're trying to pick up the pieces but there's so little that you can do. You're trying to find this goddamn girl and the world is falling apart around it. I'm not that far in, around level 20, and I still feel that theres a shitload that I haven't even seen.
I didnt really like TW2's combat system (sexually assault that poor dodge key and Quen up 24/7 or just suicide already) but the third one is pretty damn awesome. Not important but I oddly really liked the combat in the first. On the second hardest difficulty most monsters will kill you in about three/four hits so your ass has to keep dodging. They've also radically changed the potion system, you have about 3 charges or so for a potion but you can refill it for practically nothing by meditating. Makes it so that you can give a fight your all without worrying of conserving for the next fight. There is still a bit of Quen-dependence but I personally find that using my stamina for other signs such as an alternate Yrden does more defensively.
What I don't like about it...monsters are too predictable. The ones that I've encountered have a pitifully small moveset & you know how many strikes they'll take before they counterattack. Fighting humans on the other hand, you don't know when they're going to charge or come up behind you.
And durability isn't that fun, if you run out of weapon kits you gotta pay a shocking amount of money to repair it.
Movement on the horse is also annoying, sometimes Roach likes to gallop 20 feet forward then abruptly stop.
The world is also very beautiful. I don't know much about why people whined about the graphics downgrade because the game is still stunningly pretty regardless. And there's goddamn treasure everywhere, CD Projekt Red was NOT afraid to generously give loot as long as you killed whoever's guarding it.
Overall I would compare it most to...fuck that's actually kinda a hard comparison. Oblivion maybe? But without the stupid level scaling & better combat.