Well, I have a 16 piece N scale graduated pier set made by Bachmann that snaps to EZ track and it works pretty well. True, it renders an approximate  4% grade and my 0-6-0 loses traction rather than powering out with more than two cars, adding weight to loco helps. My Spectrum SD45 walks up the grade with over ten cars at 40%  throttle on an 11.25" radius curve. These locos are fairly inexpensive so perhaps an upgrade is worth considering. A cool up & over layout can be made using 13 5" straights and 24 5" 11.25 radius curves and it fits in 2 1/2 x 4 feet.