Originally Posted by ArgoMan

Yes, I have DA on my main TT training bike and it works really well with a 9-speed cassette, in friction mode. The set of shifters was really reasonably priced also, new. They'll likely outlast me, so a good investment. It's just that they are 9-speed shifters and I'm building a bike with a 10-speed cassette. But it's my understanding that I can use the 9-speed DA in friction for the 10 speeds.