Does anyone know if the new Hustler SuperDuty series is worth the extra $1K over the standard FasTrack? I know this is subjective. I'm looking at the 48". The only differences best I can tell is. 1. Larger Kawi - 19 to 23HP 2. Larger wheels and tires 3. Better air cleaner 4. Option for ROPS. Are there any other differences as far as the mechanicals. Does Hustler still use those plastic pulley idlers on the FasTrack models? Looking for the list of upgrades that makes the SuperDuty, well, Super Duty.