Before I jumped into O gauge trains about 20 years ago, I looked seriously at S gauge (previously I did HO, then N, then G trains). I researched the track systems, and learned about the Scale/Highrail/traditional considerations, and I saw some confusion and lack of standards. I wanted something easy, so I went with Lionel O FasTrack.
I just recently decided to try an S layout, and chose Lionel's S FasTrack for a variety of reasons. I hoped that the S turnout reliability and operating issues would be simplified with S Fastrack. You can look at my experience with S FasTrack on my build thread. It has not been "clear sailing" as I hoped, but I am proceeding. Go to the third page of the thread for my layout build experiences.