I drove a loaner 328 with 16" RFTs. The RFTs work actually really great on higher profile tires (50 and above) since the sidewall is tall enough to make up for their stiffer characteristics. I think it is so bad only because our tires have a shorter sidewalls.
2000 Z3 2.8 TiAg (retired)
2002 330i Orient Blue (retired)
2005 330Ci TiAg (retired)
2009 Z4 30i Space Gray (for sale)
2011 Z4 35is Space Gray
2011 535i GT xDrive Space Gray