The conflicting reports probably have come from people who have never driven a bus, right?
I used to take charter buses up to Angel's Camp often, both stick shift and automatics. Nothing an experienced driver shouldn't be able to handle simply by paying attention to what you're doing.
Your 4104's no worse than driving a long wheelbase pick-up towing a 25' travel trailer, maybe easier. Just remember that on the narrower mountain roads, don't be afraid to take your half partially out of the middle so that you don't kiss the mountainside with your back baggage bin door. When in doubt, stop if necessary. Let them hit you!
Go enjoy the Gold Country!!