We don't use a system... we do performance evaluations in person.
Regardless of how you do the evaluations, their effectiveness in ALL cases is based on what their strategic intent is.
If they have no strategic intent and are viewed as only a "required" tool of management, no program or system will ever satisfy you... generally if you are unhappy with the results of performance evals throughout the organization I say its time to tear down and rebuild the whole process... no one likes doing it, but building it right is better than patchworking something that doesn't really work anyways...
In life, there is a lot less that could get better and a lot more that could get worse.
MBA Fin/MBS HR
My views only!