Actually, I think it is:

(d) The pad BMW uses is reasonably priced, has good performance (CoF, pedal feel), and has absolutely no chance of brake squeal.

Customers visiting dealers for squealing brakes represent a very high warranty cost, and whatever else you may think about the OEM pads, they are completely quiet. Dust doesn't cost money to BMW, and they have even managed to make it a badge of honour whereby many owners are convinced that any other pad will result in a performance decrease.

My Axxis Deluxe pads were reasonably quiet, but not as quiet as the OEM pads. First applications, especially after being parked for a week, had some noise. No squeal, but a roughness. Every time you visit a dealer with a complaint it costs the manufacturer and/or the dealer money.

As an aside, I really don't think the BMW pads are very soft. SAAB and VW pads regularly wear out after 6000 km in my experience. I got approximately 40,000 km from them, so they are a middle of the road pad, IMO. The dust is because of the carbon black they use in the pad, not because of the softness.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue