Just finished the other day after picking it up in a sale. It's quite a tour de force. I started it, didn't like it, liked it, didn't like it again, liked it again and so on as it took me through it's constantly evolving mechanics. I don't think I've played a game where I've changed my opinion so frequently during a playthrough, both for story and gameplay. It did end on a positive experience, in the end. I'm just debating whether to go back and hoover up the side quests.