It's not really the valve that's bad, per se. It's more that the design of the overall system is not particularly spectacular. Ford's fix was to use a new valve cover with slightly modified interior baffles.
But yes, your car is in the 'potential problem' zone. That's not to say that every 99-00 V6 experiences difficulty. Some people never notice it. For some it's a real problem.
You can fix it if you prefer, but unless you've noticed an issue, there's really no harm in leaving it as is.
Edit: I have a 2000 myself, and I've never noticed any kind of knock. I fixed it anyway for the hell of it.