I love Incredibuild. It used to take us ages to compile Galciv2, and if you changed one header file, you'd be stuck re-compiling forever. In those days, when we would have build release days, we'd build for 25 minutes, find a bug, build another 25 minutes, find a bug, and repeat. Very frustrating when you're trying to get a build out that day.
I remember one test with galciv2 when we first got Incredibuild. I was able to completely build GC2 about 7 or 8 times before it finished building once the old-fashioned way.
Elemental is a lot bigger than GC2 code-wise so this program has been a huge time-saver.