I think it depends on the rig. We have a 4 point Lippert system on our 35' 5" Excel and get very little movement. We do not use any other stabilizing equipment. We did a factory tour when ours was being built and were told with the in house built fully boxed frame they use the 4 point would be more than adequate. In 5 seasons of use, it has been just that. This is the only experience we have so can't help with any other brand or model. I would have the dealer level the unit you are considering and see what happens when you move around in it.
The one exception we have found is when wife fires up the Splendide washer/dryer combo. The spin cycle will give you a bit of a massage but I really don't pay much attention to it. It sits on the nose next to the bedroom closet so I think the movement of it gets exaggerated a little.