My boss ordered one of these during the week.
They look great but I don't understand why they couldn't just run stock Android rather than CM11. It's bound to be far stabler.
Check out the vids of the oneplus, the OS has a number of tweaks which actually look pretty great and do add a certain unique feel to using it. Theres a whole series of swipe commands you can do while the screen is off which I think is unique to the oneplus.
A friend has one of these, build quality is great if your a fan of plastic. When your holding it, it actually feels cheaper then the usual Samsung S line.
The radio isn't too good but that could be the network he is on. I'd take a nexus over it.