Kurt has no problem powering a DF for days on end, that's where he's done the majority of his riding - we've all seen it on the Facebook videos. Are there stats that show how he's divided his time between the bikes?
I'd be interested to see what he has to say about his experiences of the DS, because from a distance it looks like he's used the bent almost like a recovery style of bike. I'm not aware of him piling on a huge advantage when he rides the recumbent, you've really got to be in the zone and fully accustomed to get the most out of them really, but he's clearly had a reason to have the Bacchetta in the fleet. Like I said, it's probably been for variety as much as anything.