UDK or Unity3D?

I currently using Unity 4, and i’ve been told that UDK is an amazing engine to use. I’ve been doing a couple hours of reading around and i’ve found that Unity is alot simpler and easier to control while UDK is basically eye-candy. Is this true? And which engine is better for FPS games?

If you need to know I want to make an FPS game like Call of Duty 4 or Medal of Honor - Warfighter or Battlefield 2/3. I have been using Unity for around 7 months now and i would say i’m at an intermediate level.

Cheers

Why choose Unity? - Questions & Answers - Unity Discussions has some discussion. You can find more just goggling.

The general idea is that UDK is better for making things that look like UnReal. Most game engines have a target type of game they “want” to make. Unity is a little more difficult to use, but more flexible. But, if you may be making lots of different types of stuff, you only have to learn Unity once.

In Unity, you have to code elevators and work out all the little glitches. In UDK (I assume) you can “drag in” a perfect elevator, but it will only work exactly the same as all other UDK elevators.