The edge bushing idea is not a good idea. I am not familiar with the EZ trem arms... However you'll never need to replace anything of that nature with a stock floyd, or schaller. Though they have their issues elsewhere. I've had the same trem arm on my 1987 kramer beratta since my father bought it when I was a twinkle in his eye and the arm hasn't corroded or needed anything to perform.
Though the idea was almost perfect the ibanez arm isn't quite a complete idea. Who knows why ibanez hasn't done anything about it. Just like who knows why gibson hasn't fixed the aggressive tilt back on a les paul headstock... The original arm is not really a problem either... But one of the engineers worked for ibanez, took their idea and made it better. It's definitely worth buying one and seeing what ya think Rich. It's not as sleek looking as the original arm holder, but installed correctly it's pretty sweet. I know I'll be buying another for my lo-pro 540r.