I don't particularly care for brush editing in the UDK. It's slow and cumbersome to drag around and re-size a builder brush. Want swim-able water? You have to not only make the level geometry, but also water volumes, and post-process volumes for the underwater effects.
In the old days things were so much simpler. Just extrude and cleave your geometry, assign sector flags and you are done.
Then I found out the editor can import text based level files. I set out to write a level converter, which would allow me to make level geometry in an older, easier to use level editor. Here is the result!
It works perfectly! The converter does a few things: