This is a great century (or less) with a fantastic BBQ at the end. The ride is well supported and most all riders I met were friendly.
I rode solo and the ride took me 5 1/2 hours (with one 15 minute stop for lunch) - but it should be noted that I am a clydesdale (215 lbs). There are only really two main climbs - Mt. Veeder and Ink Grade. Mt. Veeder is early in the ride and is only a challenge at the end. Ink grade is after lunch so you have a full stomach and the sun can get you.
One note - recommend stopping at the last rest stop which is on the Silverado Trail.
Cheers