The dreaded "Unknown or expired link" error if you flip through a few pages. Thanks heaven there is hckrnews.com.

Merging discussions is not allowed.

No checking of duplicate links, if I'm not mistaken.

Non foldable threads.

No way to watch threads of comments.

No notifications when someone answers a comment of yours.

After you have submitted a comment, it just reloads the page instead of taking you right were your fresh comment is, to allow you to continue reading where you left.

Item lists in comments are not handled.

How do you format text in comments? Nobody tells you.

Basically, if you take HN at face value, it does not look like a smart piece of software. Maybe under the hood there is a mind-bending piece of AI, but as long as it doesn't care about users, users will never know about it.

The thing was written to give a linear history(if I'm not mistaken) so that when you click next page it's what the next page would have given you at the time you first loaded the page. He could just do a page=4 query string and not use continuations and make the pages the same for everyone with the risk of seeing duplicates.

It will vote for the original if the urls are the same when you submit it. This is a simple check though.

Foldable threads are client side.

I wish it had notifications.

The other items re formatting could be easily fixed on the submission page.