Agree with the sibling comments (no editing, no downvoting, can't open hn links from a comment), and here are a few more:
When looking at a comment from a user profile and viewing the thread, it only shows the chain of parents, and no replies to the comment (much less any replies to the parents).
Several top level navigation options (most notably 'threads' and 'past') have no representation in the app's navigation menu.
Many sites don't display in the 'article' tab at all, they have to be opened in a browser.
Some sites that do display are squashed vertically, though this can be remedied by maximizing the article.
When looking at a comment from a user profile and viewing the thread, it only shows the chain of parents, and no replies to the comment (much less any replies to the parents).
Several top level navigation options (most notably 'threads' and 'past') have no representation in the app's navigation menu.
Many sites don't display in the 'article' tab at all, they have to be opened in a browser.
Some sites that do display are squashed vertically, though this can be remedied by maximizing the article.