I'm not pro-disc or anything, but anyone that thinks the aero penalty incurred is going to be even noticeable is kidding themselves. Wearing just one shoe cover would most likely more than compensate. All this aero talk is ridiculous.
Have you got any data to back up this or you are just talking without knowledge?
Only a couple of years of Aeronautical Engineering at university, which i moved out of into architecture, so no i don't have the degree.
Of course i don't have the data, but neither does anybody else which is precisely my point.
You hear someone like Phil White of Cervelo say things like "It doesn't look good" (referring to disc brakes in the tunnel) but then fail to back it up with any sort of proof. So essentially his statement is worthless hyperbole, as is basically everything else their marketing dept comes up with. Ill bet the moment they release an S6 with discs, that quote will be long forgotten, and they will be calling it the fastest frame in the world again.
By moving to discs you are able to clean up the fork crown area, and move the callipers and such down into an area that is probably pretty disturbed anyway due to the hub and spokes. So looking at just the front there is maybe a small loss in efficiency, but its too hard to tell without hard data. As for the back, the placement of the disc there would already be in such disturbed airflow that after accounting for the removal and clean up of the top of the seat stays, could even result in a small gain in aerodynamics. Now if you were to fully internalise cables with the hydraulic discs, as opposed to a conventional cabled setup, then there is a further gain to discs. So overall, with the small loss at the front, and the potentially small gain at the rear, the overall difference would likely be quite small, especially when compared to the overall drag of a pedalling human being atop a bicycle (not just the idealised bicycle).
Then take one shoe, quite outboard and in its own, probably mostly undisturbed airflow. Cover it up/smooth it out and you might make some nice cheap gains in unnoticeable-to-anything-but-a-supercomputer efficiency. Couple this with a better fitting jersey and the removal of your ponytail and moustache for added benefit.