The ZTE Open Firefox OS phone is great, but will not be a good fit for everyone. It's not for "hardcore" Android or iOS iPhone users. It's definitely not a hero phone but perhaps it will appear on one some day. I expect there will be many more phones to come.
I'm with Peter Rukavina :
Through one lens Firefox OS is a technical triumph: an open mobile operating system conjured up in two years by a not-for-profit organization.
Through another lens running Firefox OS is like running Linux on an IBM PC in 1993: it sort of works; sometimes it crashes, sometimes the wifi mysteriously shuts itself off, and while it does a lot, and is capable of a lot more, right now it does much less than an iPod touch, if only because the ecosystem of open web apps to run on it is only just beginning.
But under the hood and, indeed, infused into almost every pore of its being, it is open. This means so many things and means so much.
There are a lot of docs online and at some point I think I'd like to try a "Hello World" application!