There is a mild squeak/squeal even on the 2008 US spec DNKY (a pun on namebrand clothing) AMG brakes after a car wash or rain but disappears quickly after some minor braking once the surface oxidation is burnt/rubbed off by friction. The brakes are quiet after that.
Mine have never squealed yet. I dont track this car so it doesnt get much of a work out, of all the cars I had squeal on it occured after hard use, normally track but after a few days settled down again. The downgrade is a cost issue the excuse is the noise.