The only time I've ever seen one is when a couple of the Focus 2004 National Team guys came out to beat up on us at the Velodrome. Their bikes were Tiemeyers and very nice, I didn't get a close look as they were typically going by at 70 kph.
I haven't ever ridden one, but Michael Creed (USPS) shevled his Cervelo to use one in Zolder for Worlds.
He could have used a Cervelo or a BT.
Very aero, Tiemeyer uses the same tubes the Project 96/2000 Olympic bikes used I think.
Custom is good but can also be a disaster. Better to suggest to him what you are using the bike for, rather than saying I need a 564mm top tube and 77.2 seat angle. He knows how to build the bike.
Yaqui seems to have a loyal following here and amongst triathletes. Ves can build using the Scandium aero tubing, very nice.
-SD
https://www.kickstarter.com/...bike-for-the-new-era