I tried out TopCoder today. While I liked the problem, the Java editor didn't work for me. The remote compiling time and the lack of unit tests also made it difficult to complete the task.
I ended up coding the solution in Eclipse and the pasting it into the TopCoder window. I tried out EclipseCoder, but it didn't suit my needs either.
What tools do you use and how do you hook up your development environment with TopCoder? How does TopCoder handle submissions, and is there any way to speed up the time it takes to process them?