I've played plenty of unturned, but it got pretty dull fast. The zombies aren't hard to survive or avoid, and supplies aren't hard to gather. The only real danger I can surmise is player threats. I suppose playing with a group of friends who are terrified of death kind of eliminates that factor.
I also feel like the maps aren't big enough for more than a handful of people. If you can manage an operating vehicle, you can traverse the biggest map (at the time I played) in 5 minutes. That bothers me. Especially when there's only one location and slow regen rates for some items, if any. For its size as well, I feel like any sort of conflict would demotivate a person to continue to play. If someone ransacks the larger towns, others will have to scrounge and hope they can find what they need in the wilderness, or mount a hopeful assault on the hoarder.
Who knows? I see great potential, and I love it, but I also think some improvements are needed.