Carbonfiberboy 

Before the 300, I weighed 159, bike 18, equipment, water, and food another 10-12 lbs. The high pressure doesn't bother my butt at all. I think that's because I'm not all that heavy, I have a pretty stretched out riding position, and I pedal hard, so there's not so much weight on my butt. The 5200 frame gets most of the credit, and there's some padding in the Terry saddle so every little bump doesn't whack my sit bones. I've been told that Vredesteins feel a lot like tubulars. I've never ridden tubulars, so I can't confirm. Anyway, they have a supple feel even at that pressure. And they're fast. Rolling resistance happens because some of your energy is converted to heat by tire deflection. The more deflection, the more heat generated, thus the greater the resistance. For a simple reductio ad absurdem, consider RR trains - steel wheels on steel rails have almost no rolling resistance. Most of what is written about bicycle rolling resistance and tire pressures is nonsense, with no data to back it up. A number of years ago, Bicycle magazine did a rolling resistance test. Vredesteins at 145 had half the rolling resistance of any other tire tested.