I plan on using ME flextrack for the majority of the layout.
-G-
Be Careful using Narrow Gauge ME flex track. Our club layed our whole narrow gauge protion down, and then we realized to our horror that there are tight spots in the track. There are some tight spots that are tight enought to hold up a NMRA track gauge. I would advise against using ME flex track. We ended up replacing all about our ME track with Shinohara track.
My 2c,
Smoke