Thank you to Lotek and whoever suggested this forum on tubulars. I still have an old set of sew-up wheels but don't ride them anymore. I rode sew-ups for about 10 years, starting in 1972 when I traded my Schwinn Varsity for a really cool new Gitane Interclub - a low-end racy version of the old Grand Sport which was very popular in SE Wisconsin in those days. I rode sew-ups all through high school, and into college, over any and every surface, toured a bit with full gear, even riding logging roads in northern WI and Montana.
I built a new set of wheels with tubular rims when I bought my Trek frame in 77, and rode tubulars for another 5 years or so. It was on a week long trip in northern WI when I finally cursed those tires enough to make the leap to clinchers (they didn't hold up that well to my riding style at the time - the streets of Madison, WI).
I resisted throwing them away, and now I have this spare set of wheels with Shimano 600 hubs and Fiamme red label rims languishing in my basement. Seems like a nice set of wheels, should get some tubulars and try them again.
I really appreciate all the advice and experience people are sharing - back when I was riding them, I was not very sophisticated, even though I patched and sewed them until I was sick of it, there wasn't much of a network for this kind of knowledge, and we muddled our way through things.
As for those that say they ride smoother - hmm, with all due respect I think that's nostalgia or elitism or style-addiction or something else fogging your judgement. Look closely at the mechanics and physics of the question. I just don't buy it. But I suppose if you close your eyes, click your brake levers three times and really believe....