For sh*ts and giggles, when I put our conventional wheels back on the Calfee I only went to 100psi vs. 135psi on our 700x25 Vredesteins; lets call it the lower-limit for those tires and our 275lb combined team weight.
Handling: Significant reduction in stability and tracking through the corners.
Comfort: Quite plush up front, even over the broken pavement sections. Debbie said nothing and was unware that I'd changed the pressure.
Rolling Resistance: Definitely more drag / less responsive when climbing above 5% grades, but otherwise not much difference and no real change to average speed over our normal loop.
Out of the Saddle: Much more "springy" and heavy-feeling.