Well, it sounds like you are no introvert ;-)

No seriously, many people are quite uncomfortable when they have to use their voice for communication with foreigners.

I don't know how Coffee Chat handles the whole 'language' problem (native vs. English), but for most non-native English speakers, having to speak English is a higher barrier than having to write it.

So your points are valid too (and I could add that some people can't type as fast as they want). Therefore it would be a good idea to have 'voice' as the primary means of communication and 'text' as an alternative.

Aside from that, it usually takes less energy to type, and you can do other things while replying (or in the gaps between). Voice is more of a dedicated channel, and it's not necessarily more productive. With text you're given a chance to think about what you're about to send before hitting the submit button. I think there needs to be a balance here. Voice has its benefits, but it's not always the way to go.

These are the reasons for me. I'm fairly charismatic and well spoken. I just don't like it for this kind of thing because it doesn't give me little extra time to formulate the best response I can.

If it takes you 30 minutes to answer, of course I'll do something else. Which is good, because I don't want you to rush the answer and you don't want me to waste 30 minutes while you think of a good answer.

You probably talk a lot, I write a lot. So we are good at different things.

Talking / writing has nothing to do with anonymity, you can talk for two hours and I would still don't know who you are.

That last asterisk is a plus, not a minus, of text chat for many of us.