The climbs up to Gilroy Hot Springs and Metcalf are much shorter than Diablo. That said, I think there were some sections of the climb to the Hot Springs that were steeper than Diablo. I've never gone up Metcalf but my guess is that would be steeper in parts than Diablo too.

The ACTC website has a cool little tool which lets you compare climbs -

go to http://www.actc.org/profiles/index.php

I think the climb to Gilroy Hot Springs is listed as the "Canada Loop" here.

(errr, I just checked them out ... maybe you don't want to look)