I used to worry a lot about this kind of thing till I realized that all the extra hour or two layovers were adding up. I always take the shortest possible legal connection. Very rarely will I arrive late because of a missed connection (when it becomes tight the airline helps you out ... including putting you ahead in the security line if necessary).

Even if you only connect about once a month, a 2 hour average extra layover time is a full day sitting on your rear in an airport ... ugh!

I just made a connection a couple of days ago where I walked off of one plane and onto another ... before I would have been panicky ... now I realize that it was juuuust right and I felt really good about not having to sit around the airport at all.

Edit: in all fairness I should add that I have did have to overnight in ORD once on a connection from Shanghai to Buenos Aires (the nonstop plane took off on time but was a few hours late arriving??) ... this night in Chicago was a fair trade off for me to not have sat many hours in the airport playing it safe on other flights where I made the connection just fine.