Steve,
My experience with genuine Imron is that it is less likely than anything else to react with other types of base paints; including lacquer. Very few bikes have lacquer paint jobs anyway; but Imron has proven itself to be ideal for these applications. It's tough, perfectly clear, and flexable. For me there is simply nothing better than Imron. It is also compatable with more paints than you would imagine; I frequently mix other toners with Imron to get the paint effects I'm famous for. That's one of the "tricks of the trade".
Brian Baylis
La Mesa, CA
Nothing tops Imron in my experience.