You run into someone and regardless of whether your opponent is friendly or not, you can blast him at your discretion (unless he blasts you first) and when you die, that's it! No second chances, no "MEDIC!!!", you respawn with nothing more than the starter kit.
War Z has added a softcore mode to this by allowing micro-transactions to fund a lot of the production cost (along with private server rental) and picking what you spawn with. But the game has attracted severe criticism on its forums, citing several severe bugs that break the game completely. While i understand its in Alpha... something as simple as zombies being stuck is ridiculous for a zombie game! Some who have paid are not even able to access the game, despite having received their serial codes. Players paid for various "levels" of early access content but are now demanding refunds for the game that has apparently been in production for the last 2 years, even though the company itself, Hammerpoint Interactive, haven't been seen since before May 2012 (The website http://thewarz.com/ was registered on the 24th/May/2012). Some people have gone further to say its an out and out scam, something i am on the fence about. Hammerpoint, and by extension, War Z have an awful lot to prove before they should straight out ask for down payments.
From the videos that have started to appear on the web (YouTube etc) the bugs are very noticeable, but the game appears slick. This might have something to do with the déjà vu of seeing all the work done before on War Inc, a free to play FPS. War Z appears to be a modded and reskined version!
While i can't deny that i am excited about the new breed of MMO's on the up and coming, i will be holding out on War Z until a full release. There are to many unanswered questions for me to be confident in putting down money. Furthermore, why would i pay to be a QA tester? We have a DayZ Standalone and War Z in the pipeline - Get them when they've been trialled by fire and proven themselves