I coincidentally (didn't know about the organized ride) rode up the day before. It was hot, but in all a lovely day. I started from the visitor center, which is about 16 miles to the top, I think. Love the descent, but I had to be really careful - too many really tame bambis and moms out.... there were cars stopping all over the place to look, so you never knew if there would be a car stopped in the middle of the road (or a deer...) around that next corner. I think I've done it once every year for the last 5 or so as training for several hill climb races that I do.
Non cyclists are funny... when I got the the very top the first thing someone said to me was "you made it".... well of course I made it... it's not a question of if, it's a question of how fast