After reading some replies that said silk isn't as bad as I thought for this, I gave one of these shirts a try last night. I dressed a little warm to make sure I'd sweat, and did hill repeats and descents in my neighborhood. Then I got a flat, so I had some time to stand around not working very hard ... good test.

Yup. That's exactly what it feels like. Wet and clammy, and it sticks to you. But it's not cold like cotton is, when it's wet, at least while you're working. And it dries a lot more quickly than I expected it to. I had worked pretty hard going up an 18 % hill, and was almost dry by the time I got home. It seems to block the wind better than wool, on the bright side.

I'm gonna stick with cashmere and merino.