Had a 31' Class A without a leveling system. Movement was detected when I rolled over or got out of bed for any reason. Sitting in a campground with gusty winds blowing, MH rockin' and a Rollin'. Elvis would have been proud!
Traded for a 35' Class A diesel pusher with leveling jacks. Nice and stable in everything except a hurricane.
Bought the current Class C. On our 4,380 mile trip two weeks ago, 20 Camco Legos were not enough to "level" the motorhome in a few campgrounds - close but never enough. We spent several nights with high winds that moved the camper considerably. There is not a Class C anywhere that will not move with a 10-30 MPH side wind. Trip was in OK, NM, AZ, CA, NV, UT, and back to AR. Windy and stormy except for NV & CA.
I told my wife before we bought the used Class C a leveling system would be added. She agreed. I have an appointment in White Pigeon, MI to have the Bigfoot Platinum system installed (Platinum system is on sale!). You spend $60,000 - what's another $3,000.
I added a 2nd air conditioner also. Love that Coleman Mach 8 Cub Plus 9200 BTU AC.