Simple in concept, difficult in execution. How would you recommend the transition between the two systems be handled?
Frankly, if we're talking radical reform I'd rather keep the quarter and ditch the dime; even 10c seems too small to fiddle with most of the time, so 25c is the smallest denomination that seems worth bothering with. (Also, it's ubiquitous in mechanical coin-op devices like laundry machines, pool tables, etc.)