So, I finished it today after almost 90 hours.
At first I regretted buying it. I thought it was too clumsy for my tastes. Oddly, I forced myself to continue and it payed off (alternative movement helps a lot).
As a story AAA game, it sets the standards of this gen. Great visuals, top notch storytelling. I loved the fact that the choices don't have pointing arrows, they are not forced on the player. As a result, the ending feels completely natural. I checked other endings and there was none I liked more than mine, even the subplots.
As an action game it has its flaws. Combat is not that good, compared to Dark Souls, for instance. I wouldn't mentioned this game if it wasn't its gameplay that CDPR wanted to copy. I would like to see more variation between enemies or at least in bosses. I didn't like the Witcher senses follow the tracks or scent type of gameplay too, I found it too shallow. Crafting was useless, but alchemy was better, but the UI didn't help particularly.
Despite its flaws, it's a solid 8/10 game, I can see that some players don't mind the issues I do and focus on the great aspects of the game like its visuals, story telling and atmosphere. All in all, if you want to experience an AAA game with top production values, the Witcher is the way to go.