I try to go for "something in the middle" if it exists. Even going out of a now-small airport like SJC, things do happen. 40-45 minutes at LAX is tight because of the RJ terminal, but it is legal. 45 minutes can be tight in Dallas with terminal changes. I'll usually opt for about 1.5 hours if I can get it.
Usually, one connection time is cheaper than the other...and that factors in a well.
Cheers.