I would counter-point some of the comments on 7d2d though they are fair points from his perspective. I have enjoyed the game. but it is rough around the edges. There is a great deal of stuff there though. Its not about running naked endlessly through the woods like that other game.
With crafting I would say you should go in with the recipes known and with a plan for what you need. I would not consider the needed materials as rare, but on day one I would not think you have the time to get them all. Certainly if you have never played the game before it is not friendly to the noob trying to survive. If you read a day one how to it would be helpful.
Point 2 about online is pretty accurate. As with almost every online game, random server pickup is going to be a cluster. Seems like the avg player there is 12, and the hacks run rampant. But if you do play with people you trust - and there are closed servers out there you can get into - it is a fun experience. I am sure there is a thread where Gaffers can tell you where to hang.
For the third point, there is random map generation now and that really added to the experience. The game is "Alpha", but it consistently evolves in a good way. There is a definite design road map apparent, as the features they add seem really effective. Every major release feels like a new game in a good way.
Yeah, Zombie AI sucks. they have added a few things like wall climbers, but there is stupid stuff like you can secure your base with a ladder on square up and such. I am sure over time they will address stuff like that.
I can see where it may not be someone's cup of tea - you might watch a let's play or two before doing the refund if you are on the fence. As a dev shop, these guys are good indies.