I did try ZP, thought it was a good concept very badly implemented (was a while ago I'll give you that), I also played "The Ship" and had an amazing time there even though the number of players always seemed lacking.
The main thing is that the demo is out this week, we'll all get first hand experience then we can come back and start this afresh, but with some actual first hand experience, at the moment it's akin to people debatig the pro's and con's of a patch before it goes live