Been on Hayes Prime Pro for the last 4 seasons. They have been trouble free, just pad replacements. I never cared for a spongy lever feel and the Prime's had instant bite though a little wooden feeling. I let a friend ride my bike and he said my brakes felt "weak". He couldn't elaborate much more than that. Time to move to a modern brake setup? Thanks.
If you haven't noted power problems, how bad is it?
I'd push fresh fluid through/bleed 'em, then sand any glaze off the pads, re-bed them, and evaluate what you have vs. what you need.
That'll cost you ~an hour of work, but potentially save you hundreds of $'s.