The [-] button on top of comments for collapsing threads is very, very slow.<p>Can't this be improved upon?<p>Reddit has the same (similar?) functionality but that's quite fast.
I actually don't have a speed problem with it. It works quickly for me. Latest version of Chrome on 2015 MacBook Pro.<p>I do, however, find that comments with block quotes are unreadable on mobile as they have to be scrolled back and forth constantly. That's my main problem with the site.
On Reddit, it's just altering the DOM in your browser. If you reload the page, what you collapsed is no longer collapsed.<p>On HN, it's making a request to the server, which will remember that you collapsed that thread and keep it collapsed if you return to the page in the future.