UDK is the messiest SDK alive, I don't want to install the .NET framework SDK just to write a script with no built-in IDE (though the VS plugin is nice, you still need to work your ass off just to get it working properly), and god knows what directories you need to put everything into, replace the solution with a giant dragon statue and get the game's .exe output target path and shit stains inscribed on it and god knows what else, it is a terrible mess to set up.
Moving over to the - "Editor" (level designing tool), though it takes a while to get used to, it is quite fun to play around with, very intuitive and easy for large projects.
For smaller ones like the one I was making, it is a mess -> the brush suddenly doesn't show in some viewports, at some point you figure out you need to build the lights every time you change anything within a scene, or the omni lights won't show, or won't show the correct lighting, or some other shit, or the scene needs to be rebuilt for some brushes to show up in the perspective view.
But all in all, I've had a blast with it.
Final verdict - messy to set up and when you're a n00b,but when you get to the point where you actually know what you're doing , it is awesome :)