Andy Potts hasn't exactly been known for his equipment choices..one of which--Gatorskin tires-- likely cost him a Kona podium.

I say run a disk or disck cover unless you are really light and very gusty crosswinds and a poor ike handler. I had no issues in 2015--I descended Kienle-esque and in aerobars for most of the descents-- and it helped me throughout the entire course. Disks are only a negative on really steep sustained climbs say 7-8% plus sustained grades; even then the benefits on the rest of the course usually out weigh the negatives.