I love the cts-v, Family mans Vette I had my wife talked into trading her Denali in for one last year but I could not find a "V" locally to buy. As far as the BMW's I will take a cts-v over one anyday, Thats what my wife had before the Denali and it was a P.O.S.
Had a Denali (6.0 all wheel) great in the snow, it ate the front dif in 13k miles for whatever reason (50K vehicle). They never did get the traction control light to stay off on asphalt. I still own a GM, die hard faithful. CTS-V is a sweet ride and i agree with you, fast as a raped ape.
Usually the people who can afford a 70K ride (20k down 1000 month no insurance) are looking past brute speed and HP and towards how/if it can be used and of course status. Cadi is still a Gm product.