AAA membership is cheap insurance if you are really worried about it. I have driven from Colorado to California through Utah, Nevada, and Arizona and back again without a problem, except for some of the rough riding cra#@y roads in Utah on the original Continentals. I was happy that I had the membership card in my wallet and that it never did see the light of day.
Many of the current design run flats have an exceptionally stiff sidewall which will contribute to a tougher ride than the stock tires. I had Michelin Pilot All Seasons on for a few weeks and I could not handle their stiff ride. I am currently running Goodyear tires and they provide an exceptional dry and wet road ride. They are useless in the snow and ice.
Dunlop M3's are a true run flat winter tire that came out in the Fall. I have them on another car that I use through the winter. They may be available for the Crossfire, now.
They did not substantially change the ride of the car that I have them on. They cost a small fortune, but when you gotta go...spend the dough!
The Crossfire represents true value for the money. Don't worry about the tires. Enjoy the ride!