Extremely fun game. I was honestly prepared to be disappointed by this title but it turned out to be something really enjoyable. Still has a few problems such as performance and few bugs every know and again. The latest patch (30/01/2015) improved performance for me a little bit, however it did completely remove the stuttering and allowed me to up my view distance without a huge performance hit like it did pre-patch.

There are a good variety of side-quests to do and the world is overall really enjoyable to run around and murder zombies in. The voice acting is honestly pretty bad and the lip-synching is questionable. Some characters have fairly good lip-sync while others are just not even close to being accurate.
Also the variety of "special" zombies in this game are pretty good. Some of them you will have likely seen in other zombie games before this, but some will be a pretty good suprise.

Do I recommend the game? Yes.
Do I think you should wait for more patches till you buy? Maybe.
If you absolutely cannot play a game sub 60 fps then I recommend holding off. If it doesn't bother you too much then I would highly recommend you pick it up now.