I acquired a Q3 28 about a year ago, prior to the Q3 43's introduction. I tried a 43 but decided the 28 was good enough for me. I set up my 28 after watching a Nick Ranes video. When the v. 4 update came out, I loaded it it via the Fotos app. I noticed when when the camera was preparing for the changes, it didn't ask if I wanted to retain my profiles like the previous updates I'd loaded. The update didn't save them so I had to set up the camera, again. No big deal. I've just started playing with it and, so far, I really like the new upgrade and, to date, have noticed real issues. After the update, I noticed the Fotos app wouldn't link to the camera so I deleted the camera on my phone's WiFi setting and deleted the app. Once reinstalled, everything works fine.
Mike