Greetings,
Mr. L. MY opinion only. If at ALL possible, go with the traditional stuffing box. I personally don't like the drip-less systems. Not through any direct experience but just the idea of the whole ocean being held out of our vessel by a single neoprene membrane. Yes, there are countless thousands of these devices in use and probably an equal number of satisfied customers but the bellows have the potential of breaking and allowing large volumes of water into your vessel with no way of stemming the flow AND maintaining way. Maintenance of the traditional stuffing boxes is basically no maintenance other than adjusting every so often. I do "shoot" them with the IR thermometer fairly regularly. I had our stuffing boxes re-packed with GFO about 8 years ago and I don't anticipate the necessity of ever having them repacked in my lifetime.