My first experience with Runflats was with my 98 C5. Chevy went with these not because of performance, but because it let them get away with not including a spare tire (or designing a space to hold a spare tire). I hated them for their decision. The tires were heavy and the stiff sidewalls reduced their ability to maximize the contact patch. The only thing they did a little better than a normal tire was handle "transient steering response". There was less elasticity in the sidewalls, so jerking the wheel elicited a "crisper" reaction from the car. But even GM knew they were crap when it came to what a tire was supposed to do - give you traction, which is why when they came out with the Z06 they dumped the RFTs in favor of a 12V compressor and a bottle of fix-a-flat.
Annoyingly, Chevy chose to not include TMPS on the Z06 (because the fix-a-flat would ruin the sensors). I had a friend who managed a Chevy dealer service department who lent me the Tech-II scanner so I could turn the TPMS system on (since the car was the same electronics as the normal C5, Chevy didn't delete the hardware, they just disabled it in the firmware). This is the right combination IMO - TPMS with non-runflat tires. Maximize your performance and know if a tire's pressure is high or low. What more could you ask for?