if you are logged in, it has to check if you upvoted some of those listed items (submission and comments). If you're logged out, it doesn't need to check anything - so it's faster
In fact, if I remember right, when logged out it can serve cached, pre-rendered pages. Sometimes when HN is down or underperforming, clearing your cookies or opening in incognito will still allow you to view the site because the cache is still present.