Ok, I am a lawyer, my road tires are Conti GPs and, until about 1 year ago, I used to ride them at just under 120. I now ride at around 105-110 and did it just for the comfort factor - I do seem about 1/2 mph slower but I don't race and the older I get, the more comfort I want! Also, if it's raining, I will lower the psi to 90-100.

Interesting on the front/back difference. I sometimes go slightly lower on the rear for the comfort of my body. Sounds like I am doing that wrong.