Definitely not perfect. The default "collapse comment" buttons being right-aligned is pure insanity, IMO. They should be left-aligned so they're all in line with each other as you scroll down the page, so you barely have to move your mouse.
Fortunately this extension[1] takes care of that.
[1] https://github.com/insin/hn-comments-owl/
Also, proper hyperlink support in comments would be appreciated.