Our experience with our residential fridge pretty much echos what others have said here (also see our ownership story post). We picked up our Bighorn from the dealer for delivery, and brought it to our local campground about 20 miles down the road from the dealer to get it ready for our first outing. Our fridge had slid out of its location in the slide out. Luckily the counter for the kitchen island across from it, stopped it from going very far. Initially I found that the screws at the base had ripped themselves out of the wood block shim on either side. Then I didn't catch in PDI the fact that they did not check the water line to the fridge. I turned it on and sure enough there was a leak behind the fridge.
Since we had a trip planned, I tackled fixing it myself. We pulled the fridge out and discovered the z-brackets that were supposed to be installed on the top of the rear of the fridge was done so shoddily that one had fallen off down behind the fridge (they completely missed attaching it), and the other had like 1 1/2 screws of 4 actually sunk into the top of the fridge. There was zero evidence of holes where either of these brackets should have been attached to the wall behind the fridge. So of course with only two little screws holding that beast in place it let go. I also discovered they crushed the ice maker line by rolling the fridge over it and that caused the leak.
I ran to Home Depot, got new ice maker line and fittings to splice in a repair. Next I 'engineered' a strap system I had seen in other coaches where they converted fridges. It's a set of simple yellow nylon pressure buckle straps that I attached to either sidewall and they run around the front of the fridge about a foot down from the top to hold it in place and stop any possible rocking movement. This has been in place since we bought it and we've had zero trouble with it since. I wasn't about to go screwing things into the top of the fridge itself so I saw this as the best solution for now with what I could manage the eve of our departure on the trip. When we arrive at a destination I loosen the straps and tuck them up on top of the fridge behind it's doors and you can't see them.
My fix and issues are documented with Heartland for whatever it's worth with photos since I did it myself and should have been a warranty claim, but I have zero faith that it went anywhere since the person I was dealing with directly at Heartland was worthless.
That slide out is sagging in the center and I do not doubt it's structurally deficient for the weight of the fridge and any associated movement therein.