Most of these are beautiful, but there are a couple that make me cringe... The Cummins one in particular (http://www.paul-rand.com/assets/gallery/identity/logo_cummin...) has a very MS Paint feel to it to my admittedly untrained eye.
That's like saying "you have had a body for your entire life, don't let any doctor tell you what's good for your health".
People can listen to music for their entire lives and still have crap taste.
It's interesting / surprising / puzzling to me that someone who has spent a lifetime cultivating his craft and presumably knows far more about design than I do would choose to showcase something that appears to me to be a total eyesore, which makes me think I might be missing something.