I always found the Judy's had too much compression damping, contributing to a 'dead' feeling. Not sure if this is the issue you're describing.
I found replacing all the internals with Total Air cartridges made a huge difference. Although they're not being manufactured anymore, you might be able to get hold of some on ebay. You need to be careful though, the cap threads changed over time so not all cartidges fit in all Judy's.
If its a stiction issue you've having, I've always used Slick Honey to lube the slider on Judy's - seems to provide the smoothest action.