I guess I'm like Mhalak in not seeing quite what the advantage here is. Why would you want to use "Q E R T" on your paladin, "TAB X C B" on your WHM, and "Shift+Q Shift+E R T" on your Bard rather than using "7 8 9 0" for all of them (or "Q E R T" for all of them, or whatever)? Most players pick the keys they can most easily reach and use those across all classes. What's the benefit of switching to a different part of the keyboard just because you switched classes?