Last Summer, I took a 1500 mi trip. Greased the bearings prior to departure and changed tires too, just to be sure. At the end of the trip, the bearing buddies seemed to have consumed about 1/2 the grease. Since I'm usually in brackish water with short trips to the water, I normally grease up twice/season, just as a precaution.

The trailer is from the 50s and I have not had it that long, but even before the 1500 mi trip I didn't tear it down and re-pack the bearings. I trust bearing buddies to do their job and as long as they are consuming grease, I assume they are. I suppose that could bite me, sooner or later. But it hasn't yet.