From personal experience as someone who's had a computer since around 8 years old (and is nearing 30), I have to say that I've learned to speak more confidently, especially in less-than-ideal situations; however, I will always be able to communicate better through text.
I've noticed this is mostly the trend with people around my age as we were raised during the era where instant messaging blew up. Nearly all of my extremely intense, extra personal conversations with my friends (who I have known since elementary/middle school) were through IM. Part of me thinks this was due to SMS costs being extremely high, but I digress.
When we hang out in person, it was only to talk about school, video games, cartoons, jokes, etc., but when it came time to air out the overstuffed emotional closet, it was always through IM. Sure, it would sometimes bleed over to the "physical" world and much more detail would come out through actual physical interaction, but the conversations would always start with text on a screen.
That said, I feel that actual speech has sort of become a facade to actual "conversation". Especially in cases where one's in an unfamiliar environment (meeting someone new, attempting to speak in a different mode of speech, etc.), we all seem to just recite a script as if it's a weird vocal handshake to show that you're a normal human being. Conversations through text removes so much of the external factors that just increase noise and I believe it's a much purer, higher quality form of conversation.
[Sorry, that became kind of ranty. This was part of an enjoyable paper I wrote during undergrad.]