"It's going to take a helluva positive community response to convince me to spend twenty bucks on yet another zombie survival simulator." —Me, about five hours before I bought H1Z1.
I know. I'm stupid.
The user reviews on the Steam page are already "MIXED" and many of the positive reviews are clearly sarcastic. I know a lot of fans are responding to the negativity with, "Wait! It's early access!" I kind of agree: if you're criticizing glitches and bugs or long login times, you have no business playing early access. That stuff is a given. That stuff doesn't ruin a good game.
On the other hand, there are terrible creative decisions being made here, such as the fact you can pay real money to have an airdrop of weapons delivered to your approximate location. Another worrisome aspect is nameplates appear above everyone at all times, which means if you're hiding in a bush from an attacker, they'll just see your gamer tag hovering above it. Anyone who believes that's an okay inclusion for a game like this shouldn't be making games like this.
The login issues are to be expected. Attackers occasionally clipping through the floor as they scream "Fuuuuuuck yooooooou!" is par for the early access course. I expect things like cars disappearing and zombies failing to react when you punch them. It's even okay that my flashlight comes on at random, usually when I least want it to. I'm being fair here: the game runs a lot smoother than DayZ and Rust did when they released, at least when you're not trying to open a dresser drawer or other in-world inventories. Bugs aside, what people don't like about this game is that it sucks. And if the developers spend their time fixing the bugs like they're supposed to at this point, they won't have time to fix the things that make it a shitty game.
I got into a server and had a blast. Sometimes I would kind of lag when searching for loot, but not where it counted: during combat. This game does not deserve the bad reception it's getting over the airdrop issue. If you liked DayZ, Rust Legacy, and 7 Days to Die, this is more of the same, but in a lot of ways it's a lot more responsive and smooth.