I wanted my truck to be able to carry the weight better, without the post installation maintenance of an air bag system. So, to help carry the weight of my slide in camper without as much suspension sag, I added a set of upper Stableloads.
I thought they were a good product and worked pretty good at preventing sag. But I wanted to take it one step farther and added the lower Stableload as well. The combination worked good at decreasing suspension sag and sway.
Then I added a set of Timbren severe duty bump stops. I was less impressed with this product because it severely limits upward suspension travel. It helps support the weight but actually bottoms out more because there is less suspension travel before the suspension is fully bottomed out. Here's is a picture I took on my garage bench. Both the stock bump stop of the left and the Timbren bump stop bolt to the frame in the same place. Timbren says to set it up so that at ride height unloaded the Timbren bump stop is 1/2" above the axle. With a load on the truck it is in contact with the axle. You can see how much upward suspension travel you loose with the Timbren bump stop. It is fully compressed at the point marked by the end of the tape measure.
Timbren has a money back guarantee, and after looking at their products more I decided their standard duty bump stop would be a better choice. It actually has a higher rated capacity than their severe duty bump stop, and the compressible part of the bump stop is longer, while the bracket part on top of it is shorter. So, you don't lose nearly as much upward suspension travel. I sent the Severe duty bump stops back and installed their regular duty bump stops. They work better in my opinion. They support the weight but don't limit suspension travel.

severe duty vs regular duty
If I were to rate the products I used for helping the truck carry the weight of a camper better, and prevent sway I would rate them as such:
Best for carrying extra weight: Stableloads
Best at preventing sway: Hellwig anti-sway bar.