From what I researched, if you want soft you want air. You also will get a higher bill and depending how low you want to go, it may require a large c-notch. A static drop will be much cheaper and a little easier for the "do it your selfer" to install. If you go lower with a flip kit in the rear(roughly 6") the c-notch is not as dramatic and won't protrude through the bed. I think the latest issue of "Truckin" has an article explaining the differences. I haven't checked that out yet but I will.