I would have to say I'm definitely both. I'm definitely more eloquent when I'm typing, but as such, I usually take a while to form a response. I can be blunt but still be eloquent. Case in point, there is this woman that I honestly can't stand that I see once a week. She asked me if I wanted to know why she was doing something. I said "Not really" but with a smile, and it got a giggle out of her. It's being blunt, but in a way that is eloquent enough to not be considered rude.
I do have a tendency sometimes to be blunt and rude. I tend to be that way with my husband. And with my mom, except she's my mom and just thinks it's a "quirk". I'm definitely that way with my sister, but only after she's pissed me off.
Otherwise, I tend to be very genuine when I've got a blunt remark to say. And because of my perfectionist attitude, coupled with my need to please people, or at least be seen as kind, when I have blunt remarks to say, people tend to take that as a sign that they've "done something wrong" or that I'm joking around. If they think it's a joke, and they're laughing, I know better than to tell them that it wasn't a joke.