Just a short note on mating 0 and 027 track. It's very simple: just use mating track pins that have the appropriate diameters for each track on their respective ends. I have two 027 sidings in an otherwise 0 gauge layout to take advantage of the tighter radius curves. Those tighter curves are important in layouts with limited space.
I would also agree with those who point out the greater options and quality in 0 gauge railroading, but if you want to follow the KISS principle, 027 is just fine. Go for it!
Michael
