I regret not having a maintenance log. Most of my work winds up on GG but not all of it. It would be handy to know when I replaced a pump, part number, where I bought it, etc. Photo log is good and searchable to some extent. I'm not keen on typing a lot in. I have a paper log book but that doesn't really work. A photo log book with ability to add annotations would be best. This way I could go back and add notes. Phone photo's just don't go far enough.