I have done it once, but I understand that each year could be completely different. More than any other place, you are at the mercy of Mother Nature.
When I rode it, it started with light rain that lasted for a couple of hours, and there was a persistent headwind in the second half. Bonnie Claire flats towards Scotty's Junction was fun, easy 25mph with barely any effort. Coming back required a lot of effort and teamwork, barely making 12mph in a paceline. And the easy looking mostly downhill section from Grapevine to Mud Canyon required some effort.
The support is good, especially considering the remoteness of the place. Which bike you choose is up to you, as I don't know if you are used to riding such long distances on a tri bike. Just know that wind could be a factor. I did not need a Camelbak, rest stops are well placed and stocked. It is a special place, as Marshal Ulrich said, "expect a journey and an adventure".