[necovek]

> assuming it works flawlessly, text always does

Uhm, text never works flawlessly!

Direct face-to-face communication has the benefit of additional cues (facial expression) and ability to interrupt and explain any disagreements and misunderstandings right away.

Text has the benefit of being easily referenced (whether for clarification or historical referral), as you point out, and allows one to think through before replying (though that's not excluded from live conversation: "I need some time to process this").

As others point out, this means there is no universal answer: but it also means that for whatever tough decisions you need to communicate, it's best done with a live conversation, followed by a written note.

[Tomte]

The other way around: get the facts on the table beforehand. Written, so that everyone knows what it's about.

Then do the negotiation and decision face-to-face.

Otherwise your face-to-face talk is just everyone waiting for their turn, trying to remember which points they still need to reply to, and nobody listens to anybody else.

[necovek]

Sure, face-to-face without any prep is only acceptable for one-on-one talks (depending on the type of conversation, maybe a small number of people too).

Having a clear goal (that everybody knows) for any discussion involving multiple people is a must, definitely.