A couple of points came out of his tests, which weren't really brought out in the accompanying article. It seems many wider tires (think 32 and wider for 700C) have extra rubber and lower thread counts. Extra rubber is good, it lasts longer before wearing out and keeps you from getting flats. Extra rubber is bad, you lose energy in the flex/restore cycle, meaning higher rolling resistance. Lower thread count, well, it's apparently cheaper, but to get the same strength, you have to use fatter threads, which absorb energy quite nicely; higher rolling resistance again. However, with some searching, it's possible to find high thread count tires, although they cost more than the Perf-bar basement sales tires.
After you've made your cost/flat resistance/rolling resistance/longevity tradeoff, it's worth trying some sort of baseline ride with 10, 15, and 20 psi lower pressure in your tires. I know I was surprised to find out that I'm not faster with 100 psi than 90 psi on comparable rides. Your brain takes some of the high-frequency vibrations from road rides and translates that into a sensation of speed. But when I ride on slightly lower pressure, even though I don't think I'm going as fast, I'm getting there in the same (or less) time, and feel like I could ride further!