I purchased a used Airstream and took it in to the local dealer to have them check the bearings and the brakes. I have done this on my 55 Chevy, 64 VW, 62 Chevy and 64 Ford PU. Not really all that complicated but I had no experience with the electric brakes on the trailer. Remember this is a dealer who seldom worries about charging high prices. I asked them how often I should have the bearings repacked and he said, every 10K miles. More often, unless you consider this a hobby isn't really needed.
As far as EZ Lube axles, I am not a fan. I think these are the improved version of Bearing Buddies that were designed for boat trailers. Do you back you trailer into the lake? No worries, just use our Bearing Buddies and you will be fine. We installed a zert to pack more grease so you will never run dry! IF, and I really mean If, you follow the recommendations and guidelines with your EZ lube setup you should be fine. I think more people than you think, just pack the bearings full and feel good about things.