As someone who drives a pretty popular SAS candidate I will weigh in on this. Have you ever seen a clean SAS rig? I can only think of one or two and they are both 1st gen 4Runners (who came with a SA for two years). Most SAS candidates are turned into Off Road buggies of sorts or are no longer (truly) feasible for DD duty. Furthermore, it seems by and large that most vehicles on this site are less than 10-12 years old, and tearing out an entire front suspension system is a big deal for a vehicle that "new".
All that being said I would love a SAS swap on my 2nd gen 4Runner, but keep it mild at a 2" lift, run 33s, and look stock. However, for the ~3-4k I would spend replacing a perfectly good suspension I could build out the other parts of my vehicle. The cost benefit, from an overlanding perspective, is just not worth it.