Rainbow Road is probably my favorite deck in Expanded right now. I haven't had this much fun playing something since Donphan/Walls.
Your build looks a lot like what I think of when I envision Rainbow Road in Standard, but with some Expanded cards instead. Have you seen/thought about the
Ho-oh-EX DRX build that saw some success in Spring Regionals? My own list runs Maxie's Gallade, Yveltal BKT, and a Jolteon-EX.
I'm keeping my eye on Xerneas in Standard as the metagame shifts back toward big Pokemon-EX attackers, which are the matchups this deck really shines against. The release of Volcanion-EX is a huge coup for Rainbow Road in Standard, but losing Ho-oh-EX and Exeggcute's Abilities still hurts after Sky Field is bumped.