Best way to share system access and management with a roommate/spouse?

[spanman]

What's the best way to share system access and management with a roommate/spouse?  Should we both use the same login on our iPhone apps, or should one of us be the primary account holder and the other a Friend granted all access rights?

Related question: When a Friend is granted any and all access rights, is there anything they can't do that the primary account holder can do? I've seen the list in the knowlege base of what a Friend can do:

https://community.netgear.com/t5/Arlo-Knowledge-Base/What-privileges-do-my-friends-have-when-I-grant...

 I can't find a list of what a Friend granted full access can't do that the primary user can.

[TomMac · Accepted solution]

It depends on how well you trust the other person... that's a question only you can answer.

Just what listed except, IIRR, make new modes and control the ON/OFF in settings.