So I just got back from my little DH session. I went down Yonge three times, two times fully tucked, but I really don't know how fast I went. It didn't feel very fast, but when I coasted down the road in my car the speedo said I was going about 80 at the bottom.
All I know is that the hill felt way bigger when I was walking up it versus when I was riding down it.
Freakin' new DH setup... it's so smooth and stable it gives me almost no sensation of speed.