I have towed my 24' Grady White from New Orleans to the Keys every year for the last 15 years, (~20 hours each way), so I've spent a lot of time working on the best bearing system. Here's what I've found. Buddy Bearings are great, but you should use the ones with the relief hole that prevents over-filling. I used to drill my own holes; now they are available from the factory. I also only use the red grease called "Red and Tacky #2". I have been fortunate to never have a bearing failure, but before using the Buddy Bearings and this grease, I would find bearing damage during the annual bearing replacement. Since making these changes, I only pull the bearings every 3rd year and have not found any damaged bearings.
I just bought a catamaran with the posi-lube spindles that allow you to inject grease through the spindle to the back bearing and seal area. These are great, but did not have the clearance to allow the use of Buddy Bearings. I modified the spindle by pulling off the grease fitting, then installed the vented Buddy Bearings. I keep an extra grease fitting for my grease gun that can be pushed into the spindle when I want to "repack" the rear bearing. Works pretty well, just a little messy. So far, I've made a couple of trips of about 8 hours with this system, seems to work very well.
I'm always looking for new and better ideas. I hope this helps someone....good luck!