Yeah, with a 3G connection it's hard to maintain a stable connection for the required amount of data. You don't REQUIRE voice, but it's much easier and more "professional" like that.

You cannot pause online, well, at least you shouldn't, not for more than 5 minutes. As for pause on TOD or similar, the same applies - And if you're under ATC control, you have to be there and you simply cannot pause.

I guess i didn't remember all of that  ;D