I've tried it out a little bit. Not really a huge fan of the built-in editor. Everything that I've seen built using it seems to look outdated compared to other engines.
I tried cryengine 3, but didn't really like all the crap you had to do. Just felt inferior to the likes of UDK. UE4 though is very tricky for me, and thus I haven't really spent much time with it.
