Gasket Advice

Im thinking about buying the Percys Seal-4-Good reusable flange gaskets and I heard they were awesome. has anyone ever tried or had a problem with them?

I know one guy that swears by the percy gaskets you're talking about! He has a daily driver - a 96 trans-am that he takes to the drags every other saturday night. He tells me that the collector gaskets work fine. A little pricy but worth it!