Sometimes regardless of brand, you will get a pad that squeals when the pad composition is not just right, not oscilation squeal. But it does sound like the piston or pistons is possibly sticking, but that is usually associated with constant squeal, not when just btakimg. The burnt metal smell is normal for a couple drive cycles. Also some times youll get a new rotor that wil have a dense section, but after breaking in the new rotor, it will show with a blue or purplish color from a hot spot. These are all pretty rare. Make sure to lightly also apply grease to the anti rattle clips along the sliding edge of the pads. Try permatex extreme lube and put it on a little heavy, and double check the friction pad is still attached. Make sure the anti squeal pad is the coated, or aluminum type. You can buy online self adhesive backing plates that you cut to size, and try swapping them .