Ok, I see what you're saying.

AMG worked over/track tested different MB models into vehicles like the E55 Hammer back in the late 80s. MB and AMG were seperate (like RUF is to Porsche to this day). MB purchased AMG about 25 yrs ago and cashed in on AMGs hardcore "form follows function" credo by putting AMG logos on almost every dress up item in their catalog. AMG is still a separate arm of MB and extensivly tests items going on the top of the MB line vehicles (the SRS GT AMG for 1). With MB buying AMG and diluting the name by AMG logoing dress up kits and steering wheels, this does not mean that AMG design/development of items such as brake rotors for the SRS GT AMG are dress-up only.

BMW puts the ///M logo on steering wheels too, by your logic this means ///M division is "dress-up" only with no added performance on the ///M vehicles with ///M designed/developed/tested parts.

FWIW, The reduced weight of drilled/slotted rotors was a consideration when I chose them. Whenever I replace unsprung parts I go light. My 285x19 rears are under 50 lbs with full tread (could have gone with the "look" of 315 x 20 but didn't want the added weight). The carbon/ceramic pads are a few pounds lighter per set then OE and Aftermarket semi-metallics. With one pound reduction in unsprung weight/rotational mass being roughly equivelant to 7 lbs sprung weight in regard to performance, I am always reminded of Mark Donohue and his "froghairs" statement. Reducing unsprung weight also has the same effect as installing stiffer swaybars/springs/shocks in regard to handling. My wheel, tire, rotor and pad choices all worked toward this. My ultralight wheels are only rated for 680kg, I have to swap to the OE 255-18s when I tow.

Not at all, to conclude that would be a logical fallacy.

If you claimed that every M part makes the car go faster, as you implied with your AMG example originally (AMG AG would not have done it without doing its own testing and seeing a definite benefit), then the steering wheel example would challenge that claim.

But the existence of M labelled steering wheels doesn't imply that there are no M parts that make a car go faster. You just can't conclude that the existence of an M label, or in your example an AMG label, in and of itself, would make a car go faster.

My statement you quoted was in regard to the rotors developed by AMG for the SRS GT. I never made any statement to the effect of "if it has a tuner logo, it must make the car better". You and ard started that crap. Rotors designed/developed/tested by AMG and ///M do increase brake performance. Steering wheels don't.

You both know full well what the intent of my statement was, yet chose to direct it toward "dress up" items.

You used the example of a specific AMG rotor to back up your claim that drilled and slotted rotors must be good. I know what it looks like to me, but style is subjective, so that doesn't matter much. The only thing I know about the performance of that rotor is that it has an AMG badge on it. I simply said that isn't good enough. If there is data that AMG developed that rotor and during that product development phase they compared versions with and without holes and/or slots, that would be very relevant. And interesting. In the absence of that data, your contention was simply that it is from AMG, so it must be higher performance.

Sideline, but is that picture the standard brake, or the optional ceramic one? I am assuming you were referring to the AMG SLS GT, as they don't list an SLR. I looked at the photos. On this version, they added red seat belts too. Looks good.

Even without seeing testing/development data I would bet the standard drilled/slotted cast iron rotors on the SLS GT AMG are that way for performance. Manufacturers are looking to squeeze every bit out of these vehicles to achieve the best perf data #s possible when compared to the competition, sales #s hang in the balance.

The +$200k, 200mph supercar market is much too competitive to leave performance out to keep the ricer bunch happy.

I wonder why Indy, F1 and Nascar use rotors which are not slotted or drilled?

F1 should not even enter into this topic. They use carbon/carbon rotor/pads, these actually have an increase in friction as temp rises (driver actually DECREASES pedal force to keep from locking wheels as rotor/pad temp rises). Stand on the brake pedal at 150mph in an F1 car and NOTHING happens for a few seconds with stone cold rotors.

Nascar does, in fact, use slotted rotors on short tracks and road courses.

Not sure about Indycar, but having been to dozens of endurance races at LeMans, Sebring, Daytona, Road America, Watkins Glen..... for FIA, ALMS, Grand AM...... (all of these series are more similar to actual road cars), actually running AP Racing or Stop Tech slotted or drilled slotted rotors, and distances are sometimes more then 6 times longer vs Indy and N'car.

A major factor in the solid vs drilled vs slotted application is pad choice/compound.

I achieved instant brake bite with cold wet rotors, I found the delay annoying while towing on the hwy, increased pad wear is a small price to pay for shorter stopping distances at hwy speed. N'car never deals with wet rotors.

Update on F1s use of drilled rotors.
Austin TX F1 Grand Prix had a few teams running rotors with "cooling/ventilating" holes in Saturday qualifying. Guess it's big news because they had on board cameras showing them on track/in use.