I had installed a set of the non-OEM running boards on my 2001 X5. And having put them on, and then installed the OEM ones on my 2004 X5 I can tell you they are light years difference in how they attach and the quality - to say the OEM's were more sturdy and better integrated. The rubber dots on the non-OEM RB's fell off consistently and since they were from China I had no way to get anything to replace those. From a cosmetic point I thought they looked good and were less $ and they are still on the car with the guy I sold too. But if you take them off the surface underneath would have been pretty unsightly from the install.

I also snow ski and reaching my ski roof racks using the boards as my step is a necessity. They are quite functional for me and why I searched for an X with them.

This debate of RB versus non-RB has been raging for years on the E53 forum and you will find both sides of the argument there. :D