I guess I was wrong about the length...it's only a little longer and has steeper peak sections than Sierra:
http://lowkey.djconnel.com/2010/week6/
http://lowkey.djconnel.com/2011/week2/

I agree about it being harder. It's actually a great climb because it's so secluded....you feel like you're in your own little world.

Both are doable....Caleveras is mostly flat except for that turn off of Felter so you get to rest. Then there is the corner rest stop after the 680 junction to refuel.