On https://confluence.atlassian.com, the comment Editor is not loaded on page load (like it is in "Download" Confluence installations), but only after clicking "Add Comment". This reloads the page with the parameters "showComments=true&showCommentArea=true", in which case the editor is loaded. This probably keeps some load off the server if you do not have a lot of commenters.
Can I have that in the download version of Confluence installation, too?