I agree, I just took delivery of my new car and the run flats rode very harsh and heavy compare to my aftermarket wheels
I heard the Michelin PS2s are great but expensive and wear fast....I had Pirelly Rozzos and were very smooth and light BUT they wore very fast at 15k miles and the grip was good but not excellenet. the SO3s are a bit harsh and heavy tire. So PS2s were going to be ($$$$) and one fo my friend told me of the toyo T1s (brand new model). so i got those instead..
My reviews:
- At the beginning theyn were ok, These tires need a few hundre miles of wearing to really show off. Now after about 3k miles the ride is very smooth, they grip excellent in rain and dry (a lot better than Pirellis rozzos) and look good IMHO... Also they are light and when combined with a light wheel you car is more agile and reduce some rolling weight (about 100lbs of rolling weight). A good test is for you to try to pickup your standard whell and RF with one hand and see how high you can lift it you will be surprise in the difference in weight.. also I dont care much about RFs, i have a spare in case i need one.

 

I have heard nothing but great raves on the Toyo's. I love the tread pattern look too

 

I posted this last night - Car and Driver reviewed 11 high performance tires on the E90. Basically, the F1 GS-D3 is the one. All tires were inflated to BMW recommended pressures and they included an independent test driver who performed tire testing for Michelin for more than 10 years. He drove the tires in a "blind" test, he purposely did not know what tires were on the car, providing subjective comments to back up the quantitative test data.


http://forums.e60.net/index.php?showtopic=17888

 

I currently have Dunlop Sp1 Runflats fitted, had one replaced the other day due to puncture ( luckily insured ! ). I have only done around 10,000 quite careful miles & the tyre fitter said the tyres only have a couple of thousand miles of life left, this wear rate is far worse than any other tyre I have ever had. Is this normal? The wear is quite even, not due to tracking or anything.
Another point, I asked the fitter what non-runflat he would recommend, as I want longer tyre life & better comfort, he said he would always fit runflats to my wheels ( 18'' style 123 ) as if a non run-flat punctured, the wheel would get damaged. Is this true?
Any advice appreciated..

 

See here: Non RFs!

I guess it's possible that the wheel could get damaged but unlikely and as I'm doing buy the spacesaver spare...