I also own the standard 15" Continental tires with the silver finish 8-spoke rims. Like 'em a lot. The car has excellent handling, braking and the ride quality is ver reasonable. The 15" non-runflat tires are easy to repair and cheaper to replace. I am not convinced about the "advantages" of the pricer runflats.
When I ordered the car, I was having a diffult time deciding between the 7-hole and 8 spoke design. After much debate I went with the silver 8 spokes wheels (I hate white wheels, sorry but they look cheesy and are a pain to keep clean) and couldn't be happier. They emulate the look of the S-lites found in the
MCS. Tires look bigger due to the spoke design too.
I don't completely dislike the 7 holeys, but my main caveats with them is that they look "nerdy" and also make the car look smaller. But the holeys are also the lightest tire/wheel combo (About 1 to 3 pounds lighter than the 8 spokes) and give the car a classic look.
To me anything above the standard 15" tire/wheel size is purely for show. I like the 16" 5 star wheels but regret that MINI forces you to settle for expensive runflats if selecting this type of wheel. The 17" wheels in a MINI are just plain stupid.