In the TT I did Saturday most participants used regular bikes since it was mostly uphill. But there was one fast, flat section (I was doing 25mph or so) that was nearly a mile long. I'm curious: on a typical rolling TT of say 12 miles or so, how much faster would the aero position of a TT rig make you vs. a typical racing bike, expressed as time saved? 20 seconds? 40 seconds? There must be research on this stuff.
I'm assuming this would be a minor factor on a mostly uphill course, but I'm sure anyone who had a TT rig would have used it on these roads Saturday (and they did), it was not all pure climbing.