I put it in my boat after the first season, and have not touched it. I would not say that it is dripless but drips a lot less than normal packing.(Maybe one drip every 5 minutes vs. a few drips a minute with normal flax)
Its excellent lubricity and high thermal conductivity supposedly keeps the shaft running cool at all speeds, but that is hard for me to tell.
All I can say is that I have had no issues and am happy with the switch to this packing.