I'd have though the title of this post was an example of "stating the obvious", but apparently (at least according to a number of random comments I've come across recently), it isn't where some are concerned.
I'm going to try and keep this short, because I really want to ask here is: what is your impression of the relationship (cognitive, linguistic, etc.) between speech and writing?
For me, writing is definitely "easier" than speech as far as enabling me to produce actual, communicative content.
I used to imagine this was probably the case for pretty much everyone. But why, then, did my interactions with people tend to go so much better when I "met" them via e-mail first, as opposed to in person or on the phone first? I wondered well into my twenties why my co-workers were insisting on using the phone so much when there were all these wonderful text-based tools (such as email and instant-messaging) available.
But eventually I heard enough comments from other people such that I realized that I was considered unusual on the basis of my favored communicative mode.
And that's still really difficult to acknowledge, because, well, it feels so normal inside my head as far as this stuff goes.
But I digress.
If I was going to rank communication modalities in terms of how brain-friendly I find them that list would look something like this (favorites first, least-favorites last):
1 - Asynchronous text-based (e-mail, bulletin boards, etc.)
2 - Realtime text-based (Instant Messaging)
3 - Speech prepared in advance (i.e., something I've written down and can read from)
4 - Spontaneous in-person speech, supplemented by notes
5 - Spontaneous in-person speech, no notes
6 - Telephone (except if it's someone calling to say, for instance, "Hi, I'm coming to pick you up" -- those calls are OK because they are usually concise, clear, and giving me Very Important Data about when and how a transition is going to occur)
Of course this list does not include every possible means by which any two or more people might communicate. There are many forms of communication (diagrams, art, music, 3D models or sculpture, gestures, etc.) that can often "say" things that words simply aren't up to the task of. There are also forms I don't personally know how to use (such as American Sign Language) which I haven't included just due to my own lack of experience with them.
Nor does the list above represent my preferences at all times, with all people. There are some people I can communicate rather a lot with via realtime text chat (sometimes moreso than via email) just because our vocabularies and cognitive styles seem to be similar enough to allow us to use far fewer words than either of us might need to with less-similar people.
Nevertheless, it's a pretty accurate ranking when it comes to basic, everyday, language-based communication. In general, if I get tired, stressed, sensory-overloaded, or just plain "talked out", speech is the first thing to go.
I can usually write long after I've lost the ability to make speech make sense, and I can write asynchronously usually even when I can't respond fast enough to make an IM conversation worth having.
Furthermore I have a lot more knowledge-access in writing -- for years I thought I knew a lot less than I do about certain things because I'd been trained (mostly by teachers) to believe that "if you can't explain something verbally and spontaneously, you don't understand it".
But once I started writing out more of what seemed to be in my head -- as I fit the shapes of thoughts to phrases that way and saw them laid out in front of me, I found that I actually understood a lot more than I could possibly explain with my voice.
And I've heard the same thing, or things very similar, from many others on the autistic spectrum, including some of whom were thought to be basically unthinking or mostly unaware of their environments until they were given the opportunity to type or write or whatnot.
So, what are your preference rankings for this sort of thing? What contexts do you prefer different types of communication in, and why? And do you tend to assume that someone's writing ability is predictive of their speech ability, or vice versa, or not?