Scooby was actually a very easy ride to operate as a cast member. But it was one of the last rides staff learnt due to the complex evacuations. Wild West Falls was the most intensive due to the constant walking up and down the load platform. I was trained on Superman, Scooby, West, Batwing, Lethal Weapon / Arkham, Batman, Tunes Ride and Kids Rides / RoadRunner Roller Coaster before leaving in 2013.
At that point I'd say the most reliable major ride was honestly Wild West Falls, Batwing and Superman. Before the Arkham conversion it would have hands down been Lethal Weapon. As far as ease goes I was only an attendant (not the one sitting behind the main control panel) most of the time. So from that POV batwing was very easy (but also incredibly boring), followed by Superman, Scooby and Wild West Falls.
As a supervisor they were all very easy honestly until things go wrong, then each of them have their quirks. Scooby is the most full on by far for trying to reset faults to avoid an evacuation. Followed probably by West. If superman decides it's going to fault, generally we just let it do it's thing as it's not as intense to evacuate compared to Scooby / West.
Certainly had the most fun IMO working on Lethal and Superman (apart from Tunes and Bat Ride before closure)