The choice depends on the trailer's Gross Vehicle Weight Rating (GVWR) and the towing vehicle's capabilities. Electric Brakes are the most common for utility and horse trailers, requiring an in-cab controller. Surge Brakes (Hydraulic) are preferred for boat trailers as they are self-contained and water-resistant. For heavy-duty industrial applications (over 10,000 lbs), Electric-over-Hydraulic (EOH) systems offer the fastest response time and highest braking force. Always ensure the system matches your axle capacity (e.g., 3,500 lbs, 7,000 lbs, or 10,000 lbs).