serpa,
I didn't even know that there were 'lower' Stable Loads until you mentioned them. I went to the website and can see they would be a pain in the behind.
I've been using the 'upper' Stable Loads for a couple years and they were the icing on my leaf spring cake. No moving parts (other than deforming rubber/plastic); nothing to adjust or fiddle with.
I agree with the poster above that there should be a lot of step-by-step trial and error when it comes to beefing up your suspension. It's called 'fine tuning', like adjusting the strings on a violin. Try not to be tone deaf. Just try to avoid any upgrade that has a lot of recoil. That would be air bags and extra coil springs. Only dumb old leaf springs have a minimum of recoil.
As far as adjusting your suspension for rough roads, I recommend releasing one side only on your rear anti-sway bar, just like i did for 40 years with jeeps, land cruisers, scouts, and pick ups. Only one nut removes one side. Yes, you may have to lay in the mud, but only for one nut. Use a plastic zip tie to hold the swivel bar end to the main bar. My extra leaves and Stable loads do such a great job, I detect a small difference using or not using the factory anti-sway bar on the highway.
So, tune that fiddle.
regards, as always, jefe