Originally Posted by JCL

They seem pretty expensive for what they are. 2005 4.8i, rotors only:

Stillen Sport: $788
Centric Premium: $492
Centric Stoptech Drilled & Slotted: $552
OE BMW (Web price): $514

The Stillen look comparable to the Centric drilled rotors, if you want drilled, but for 40% more $. What you will need to check out is the vane design. The Centric rotors use the factory vane design, instead of cheaper straight vanes that don't provide the same cooling. Stillen's web site notes that they use curved vanes on their more expensive rotors, but not on the Sport. Might just be that they forgot to mention it, but the web page makes it sound like it is a straight vane.

Given the price comparison above, that is why I have stayed with OE rotors, and just found a good price for them.