I have 23C GP4000 tires. I've been running 95 front, 105 rear for over a year with no problems. It helps a lot on rough roads, and seems just as fast. I think the flexible sidewalls in the tires help, too. The usual 110 in both tires isn't any faster for me, but there's a lot more vibration.

I'm around 170 and 20 lbs of bike, and the chart is very close to those pressures.

EDIT -- I tried weighing my front wheel while on the bike and get somewhere between 44% and 48% of total weight on the front wheel. (It's hard to get an accurate measure) So the chart says 90 front and 105 rear. Maybe I'll try that on the next ride.