Here is me working with my level editing tool that I am developing in the unreal 4 engine. Its designed to be in game so it allows you to build levels with your friends and it will even allow people to play the level while it is being built!
Full Video link is here
https://d.tube/#!/v/thecastle/QmRXkTfRUAfpqvuiaXtmMeTW4RbBZsgejQKztX5zxcMZqp
So with all of this said you can see the editor in action and get a feel for what it is like to use. I plan to get the next version of the level editor out this weekend with the ability to build basic blockmesh levels in Revulsion 1 a week or so later.