I think you will have a hard time getting anybody angry here. I have not seen a better bunch of guys in an online forum. I asked about this and I think the consensus is everybody runs dry, a few guys don't even use the pan.
Anyway, have very little experience with water pans and what little I do have has not been good. I think most guys are running with the pan empty, wrapped in foil. It is just too much of a mess to figure out how to throw out brisket drippings without an expensive visit from your plumber at least for me. I asked about maybe using it to hold some smoking wood but I don't think anybody responded to that idea.
I did just read on a food safety site that a bowl full of water in a smoker is good from a food safety perspective because it creates steam that kills bacteria. I don't know if that is relevant at the temps most people are running in WSMs.