Early W211 AMGs use the electro-hydraulic SBC (Sensotronic) braking system, covered under a 25-year warranty tied to manufacture date, and a recurring point of buyer concern. Some find the SBC feel numb; separately, owners consistently praise the cars' outright braking power.
SBC Sensotronic brake system: warranty and feel
Mercedes-Benz E55/E63 AMG (W211) · mechanical