Comment editing: too narrow panels (in my subjective opinion)

When one edits a comment, the comment block is vertically divided in a 50%/50% manner between the editor and the preview sides. Both windows hence turn out to be pretty narrow. See the picture below (a picture may be better than 100 words here).

I know that this is quite subjective, but I suggest to have the editor part on top of the preview one here. Also having the editor height automatically computed would be good.