There is a thread in C&V on it. Great organization and support. Bargain for what you get. Beautiful scenery. I am a flatlander, but manage to get up the mountain with enough gearing.
The 75 is more tiring to me. The 100 gives you a chance to get on the big ring/small cogs some and air it out. Now if you were not in a hurry getting there or going home, you could take a couple of days in the Central Va area and get some more good riding in. You could take some rides on and around the Virginia Capital Trail. Also could do some hiking in the Blue Ridge. It could be a good vacation.
The 10th Annual Storming of Thunder Ridge - May 19, 2019 - Storming of Thunder Ridge Storming of Thunder Ridge - www.stormingofthunderridge.org
https://www.virginiacapitaltrail.org/