I use it all of the time. I have never had a tire degrade from the use and it seems to last as long as any other dressing. It works much better if you apply it in the sun when the tire is warm. I like it because if I don't scrub my tires it still gives a nice, black appearance that's not too glossy.
$4.88 at WalMart and a can lasts me a year for two vehicles.