For me the best album of the last 3 AC (not having made the first). While optimization is poor. On my PC it runs between 45 and 60 fps in high HbAo + FXAA and with gtx 770 2GB and i5 in high quality so rather comfortable. This game is beautiful, the lighting effects, the realization buildings, animation, crowd, atmosphere etc. We can rail against different bugs (freeze, which NPC anything) and technical shortcomings (such as clipping and mushy textures in the distance) but also a game ubi what. A ubi game bug is not a ubi game. But this is trivial compared to the overall beauty of the title. The scenario is pleasant and the side quests multitudes are (very) interesting.
In short if you have a good machine (at least gtx 680 as requested), please!
