I was on one of the "DE" first person servers:

-No server crash or client crash throughout the 2 hours I played. Did not encounter any players to check how PVP performed.
-Server performance was good, did not experience any lag.
-Enjoyed it very much, it was immersive, zombies everywhere and I felt they were a threat, was trying to avoid them at all costs.
-Died to zombies from having to shoot my gun at VMC because I could not "flee/sprint" due to plate carrier. This may need some tweaking as I felt quite punished. Not sure about it yet...