I am aware that banked curves are employed by the French group that likes to set the Lego train speed records, but I haven't seen any used in a more conventional set-up. I know that my Horizon Express likes to tip over in curves given the opportunity (and a long enough straight section to build up the speed...). Banked curves should solve this issue - one plate's height ought to give something like ten degrees, working from memory. Has anybody used these in their layout?