QMI vs PPP - which one is better?

The tutorials explain how to set up the 3G/4G hats using PPP and QMI protocols, but which one is better? I’m using Quectel EC-25x modules and either the SixFab SIM or Verizon SIM. I’m currently using PPP, but wonder if I should switch. I have two applications: #1 is 500kbits/sec data only, the other is HD video (1280X960@30fps). BOTH ends are mobile. I use LogMeIn Hamachi to deal with the IP addressing issues. I need to be able to automatically reconnect if the cell signal “disappears” and later “re-appears”. I don’t know how much of that is handled by the various protocols, and how much I’ll have to do in a cron task. But if someone has some answers, I would like to know.