I have a 9' by 12' layout. Originally I use lionel 0 gauge tubular track that I had in storage for years. Several years ago I was able to pick up a quantity of supersnap track at a good price (brand new) and so I began to change over. To me they looked much better and came in convenient 20" and 30" sections (also 40"). I had trouble getting supersnap switch tracks so I mated the Lionel 022 switches and they fit well with the supersnap. Last year I found a source of supersnap switches (Trainz) at a reasonable price).
Though no longer made, supersnap pops up on EBay and other sites (Eastern Depot, RMT, etc.) and I have found just about what I wanted to run three separate trains plus a trolley plus multiple sidings. Unfortunately you just have to keep looking (do Google searches).
JohnF