RFTs do work but only in europe where the roads seem to be in far better condition. My E90 now runs on non RFT but wifes new Bclass has come with RFTs and the ride is harsh to say the least. Her old Blcass had 18" on on RFT and was far better.
Its not only BMW that are making the mistake with RFTs in UK
Will be ditching them as soon as I can for non RFT and a spare in the boot as luckily there is a space.
F30 335i M Sport