Type-R reels were offered to perform the best, by reducing weight from every components from stock Daiwa TD-Z Japan, tournament model reels, at frame, gears and etc. Type-R also reduced brake force margins to add more casting distance, and the casting performance is tuned for anglers with expert level of casting ability. The trick is at Type-R spool, with modified brake rotor.
2506C Spinning model has special tuned spools and red line rollers specialized for 3-5lb fluorocarbon lines for finesse drop shooting.