I find them quite natural. When reading a response, the subject of the email has already clued me into the context, I really don't need to re-read what I already sent, even an edited version.

Top answer with my email below for reference, if needed, is what I prefer.

Well, fair enough. I find it natural, your mileage may vary. :)

Do you also find the top-posting style of blogs, twitter, &c awkward? I really do think there is something to be said for putting the newest information first.

I don't mind blogs, because posts tend to largely stand alone. They're like consecutive articles in a magazine. It can be a little annoying in the case where, say, a post is tagged, and I click on the tag to get all related posts, and they cover multiple pages and I need to walk to the last page to get the first post. That can be a little annoying.

Twitter is a little annoying for me, when there's a discussion going on, where it's difficult to get the context of each twitter message. If the tweets stand alone, as is often the case, I don't really care.

Back in the Usenet days, I was a scrupulous interleaved-response writer. Quote the specific sentences or phrases being responded to, followed by my response. I prefer to have that bit of context, right by the response, in that order (quote then response).

Exactly, I used to interleave...but the times are a changin and there's not much we can do about it. Twitter, FB, blogs are not going to change (nor should they). OP is about 16 years too late to this argument.