Brian,
There is some tire noise in the IS with the 17" Potenzas, but not as loud as the SVT's KDW's. all the articles I read said the same thing, loud tires. I think it's compared to other Lexis and the competition (3 series, A4) There is no wind noise, however. I'll have to check engine speed @ 70mph, but for some reason I remember 3000rpm is about 66mph. 2nd and 3rd gears are taller than the SVT, but 5th is shorter. What it is nice for is 75+ mph acceleration w/o downshifting. But I'm sure with another cog it would get 2-3 more mpg.