What is the real difference between a high TPI count road tire and a low count one, other than price? The marketing department will of course tell you that it makes a huge difference in suppleness, ride quality and strength. But I'm skeptical. As far as I can tell one deflated, kevlar beaded road tire is just as flaccid as the next and I have a hard time believing that the minute differences between them deflated suddenly becomes significant when 100 psi of air is added to them. The air still generates 99% of the rigidity of the tire, as far as I can tell. Furthermore I have a hard time believing that the cotton/silk/nylon/whatever cloth in the sidewall influences the rigidity under compression much at all anyway. I can see a thinker coating of rubber making a structural difference in the sidewall but a simple TPI count just doesn't mean anything as far as I can see.
So is this just plain old "more is better" marketing, or is there a science to it that I haven't seen yet?