"But is it more aero?"

I'd say absolutely no. More frontal area (higher saddle, arms angle more acute and elbow pads higher) and upper arms are more cylindrical for starters.

Neither position is UCI legal, and jens isn't doing Tris (so the comfort part isn't *as* important, as you're already horribly uncomfortable from going as hard as you can for a TT).

It'll be interesting to see how his times compare with his other position, with similar and any gained wattage, though (hopefully you'll tell us, jens).