re: Is there a negative with higher speed rated tires?

All I can offer is that I had "V" speed rated (144 mph) Michelins as the original tires on my Volvo. It topped out (or, more likely, was limited) at ~115mph. I don't recall the tread wear rating, but I'm certain that I got over 50,000 miles out of the originals. (It was a front wheel drive, non-turbo, 5 cylinder, so there weren't ANY smoking tires involved!)