FWIW, I agree. I'm a little heavier than you these days, but when I weighed about what you do, I tried everything, from 19mm tires at 120 (really high in those days) to 37mms at around 70, sometimes lower. Grant petersen at Rivendell has written about this, too, and as I recall (check it at www.rivbike.com) he doesn't recommend the standard 23mm tire for anybody over about 140 pounds. Several years ago I put 32mm or larger tires on both my road bikes (Atlantis and rambouillet; plenty of room), and I'm never going back. I do most of my riding these days on 35s at 75-80 pounds, and there's no consistent difference in time for a 12-mile commute I've done hundreds of times between those and 700x25s at 105. There are several advantages to larger tires at lower pressures, and no disadvantages that matter to me.