The biggest difference I noticed from having both was the pin design. I ran the lock right hard. V8 and 4ds. I also broke 3 stock stub shafts before getting 35 spline outers. I never broke the pins. Eventually the teeth wore down. I think I ran it 3 yrs. I even had the teeth edges recut and ran it a while longer before giving up on it. I didn't notice a difference in teeth.
The lock right pins are solid and the springs push against the pins. Spartan the pins are hollow and springs are inside the pins.