I find it really interesting that people are saying there are grey 'bars' between posts.
I don't see that - I don't see it as 'grey bars' - the greay space between posts is the same color as the rest of the background. The post's content (and ONLY the post's content, not the top metadata) is highlighted with the white background. The small metadata (link to post, find all posts by, date, and up/down votes) are part of the background, 'hovering over' the background and post, as it were.