That is about the only complaint. I have 545Rs and absolutely love them. The ride is much improved since you do away with the runflats. The rear tire/rim combo alone will save roughly 8-10lbs each. I picked each up(stock and HRE) to compare. Traction is much improved also.
After roughly 2 months on the car the only thing I will say is to becareful of potholes or rough roads. Here in NY there are some bad ones this time of year due to the freezing and thawing from the change in temperatures. With the lower profile and softer sidewall, you can potential bend a rim.
Also I still have yet to have the car recognize the tire pressure sensors. Chuck had some initial problems but I wasnt that concerned. At some point I have to call HRE to see if they have any ideas. I am sure we are just missing something since I purchased them used and the orginal owner's car recognized them fine. I plan to figure it out in the spring.
In the end, yes they are expensive but well worth it. I can not stop staring at the car...
Here is my set 545Rs fully polished which I am sure everyone has seen before...
This is when I had them installed:
This is all cleaned up: