I did my very first Road Time Trial tonight and absolutely loved it.
10 miles, 25:39 mins 289 watts.
If you have never done a time trial with a bunch of roadies give it a go. Its not like a normal bike leg from a triathlon sprint race where you may go at what you think is 100% effort, but don't really as you need something in the tank for the run. It really is all out effort from the moment you go until the finish line.
For any of you out there that have never tried one find a local bike club and give it a go.