My layout is about 25 X 14 in size. My mainline is FT. All of my O72 switches are FT. My sidings are MTH. Although FT is easier to work with, there are some qualities that I think MTH does better.
1) Better uncoupling track sections
2) Sturdier lit bumpers
3) Lit terminal sections that I like when powering a siding
MTH also gives me a different look for my sidings
I am very happy with FT and it has held up well and performs next to flawlessly.
