Without a picture or video its hard to tell about the fisherman's knot. Probably you will have to experiment with the new knot to see if it's stronger, or weaker or just as good. Then let us know what you found out.
I have used the Pitzen knot for years and never knew the name of it til I read this thread and looked it up. More recently I have been using the clinch knot and the improved clinch, especially on streamers. Good luck with your search. Jim