Had Timbrens on my '03. Worked very well and happy w/ them. Over time though, I think the springs lost some stiffness as the Timbrens were making contact pretty much all the time w/ the axle. Lifetime warranty w/ Timbrens.
New truck, I went w/ Torquelift Stable loads (upper and lower). Uppers make contact all the time w/ factory aux springs, but ride isn't too terribly harsh. Afterall it is a truck, not a car. Have heard contrary to another post, not supposed to trim the uppers so they don't make contact unloaded. Lowers are a bit of a pain to engage/disengage, BUT what a difference they make engaged!! No sag in conjunction w/ the upper SL and no need for a sway bar. Lifetime warranty too here.
For the OP, you can see each has there pluses and minuses. Patience is required to install any of them. Why can't Ford, GM and Ram offer a true air ride susp like semis have?