I've never bought the same tires twice, because I like trying something new everytime. If I don't like them, I'd sell it and try out other tires or maybe buy the ones I used to like.

That said, I like my Krylion Carbons very very very much, however, I do not intend to use them again as I have another set of Michelin tires that I want to try. (Lithion 2, in the recommendation of Dr. Banzai a long time ago.)