I will say the noise level is enough that I am removing them in the next week or two for the off-season until June.
The rails alone whistle around 55mph, and putting pads on for the boards shifts that upwards to more 65-70mph.. but the bigger pads produce a low frequency thudding/wind buffering noise at 70-75mph, which is also unpleasant.
Considering how dead silent this car's cabin is on the road at serious highway speeds, the added noise is noticeable and something I won't want to deal with for 9 months of the year if I don't have to. For me this will likely be a summer-only accessory.
I think some 3rd parties like Thule may be making rails now, maybe they are more low-profile or aero?