The bits about the Countach are definitely true. The thing was a monster and it made no apologies. If one was willing to beat the crap out of the car, it could turn in some awesome numbers, but it was never anything but a nightmare that required a thorough man-handling to drive.
The 427 Cobra isn't quite as bad as all that, but yes, you definitely want to be sure you're pointed _straight_ when you put that skinny pedal on the right down to the floor.
As for the big-block 'Vette's, well, I'd still give my left arm for my buddy's '68 427 convertible with the 4-speed. Just for the way it sounds and looks... Mmmmm.
ZV