Maybe in some cases it is helpful (for both parties) if it is written down. However, in my experience, a conversation can often be very helpful as well - you can ask clarifying questions etc. It becomes more of a brainstorming together. Has helped me many times (on both sides of the conversation).
I find the instant messaging is even better(for informational conversations).
It gives you time to think, can decrease miscommunication and the psychological element of conversation(giving more clean space for the informational element) and increase the depth and details of a conversation.
Completely the opposite for me. What would be a couple of minutes of conversation is stretched out to an hour or more. And no point starting something different while waiting for the next message.
