We installed them and it sppears they increase the footprint quite a bit. HOWEVER, we had a leaking airbag, the coach was riding slightly lower in the back, and we went through a difficult construction area and lost one in there somewhere. (mere inches of clearance between the road and the rear snap pads at the time). I contacted the company about the missing snap pad. Unfortunately we were under the one-year warranty and they said they would send me info on how to get a replacement bed that has not yet worked out yet. Meanwhile, one of the other feet was somehow bent and the snap pad was VERY close to falling off - we had to replace we have to order a new jack, and it will take months, (because the cost of repairing the bent foot is about the same as the cost of a new jack.)
that has nothing to do with the performance of the snap pad, I suppose, but it's odd that the foot could be so badly bent. As far as we can determine, it happened at the state park where the while we were trying to level it at Hunstville State Park, that had a large drop off of the asphalt area.