I have used both Unreal DK and Unity 3d. On any day, I'll pick Unreal based technology over Unity3d. Unity 3d was a total pain in the neck and is more suitable

I have used both Unreal DK and Unity 3d. On any day, I'll pick Unreal based technology over Unity3d. Unity 3d was a total pain in the neck and is more suitable for art-heavy and relatively less programming kind of games. Unreal is far more mature as a platform and you can do a lot more with it. (The code of the internals sucks a bit though).