I just installed my Geiser and Deaver+3 springs. I was very worried about the ride becoming too sfiff, but that definitely is not an issue. The truck definitely does not have as much body roll and the ride might be a tad stiffer on-road, but nothing noticeable. As for ride improvements, I can't speak for off-road use because I have not had a chance to give that a shot, but I don't see the huge improvements that everybody else has talked about for on-road...... maybe 20% better? That said, I am very pleased that I will now be able to fit 37" tires on the truck which was my main reason for doing the upgrade. If anybody else really wants 37s and is tight on money, I would suggest just doing the Geiser springs in the front and staying stock in the rear. I don't think you would be too unhappy with that setup and could add the Deaver springs later. I gained 2.5 inches up front and one inch in the rear. Hopefully I do not experience too much sag with either set of springs as they settle.
All that said, I would still love to have another two inches of lift to get a certain look. Am I going to start breaking things, or wearing them out much sooner, if I add Geiser's two inch leveling kit to the front and two inch lift blocks to the rear? Can the changes that I am suggesting be done? Per my understanding, the ride should remain about the same except for the ill effects of raising the center of gravity, but I'm not sure if the other components, especially those on the front, can hold up with another two inches of lift added. Thoughts?