Should I Upgrade

@BarryW

You could share an individual membership between the two of you if you wish. All data would be shared equally among the both of you. You would add your account to all of your devices once all of your data is in your membership. Then you'll remove the Primary vault which is not part of the membership (mobile devices).

I'd suggest working with two devices and once you have those working you'll find it much easier to add in the other devices. That's how I started out years ago. It served me well.