Curious what is best practice for tracking 404s?

With a recent site overhaul, I have pages in my stats that someone is using to reach my site but no longer exist. In its reports, Koko seems to be listing the URL that was requested rather than listing the 404 page that they were ultimately shown. I'm wondering if this is a deliberate choice or just an artifact of when Koko records the incoming request. Does this match other analytics tools' (e.g. Google Analytics) behavior? It's not clear to me which is considered "correct" since they're both useful information although it would be nice for analytics purposes to know the aggregate number of views that ended up on my 404 page.

FWIW, if you're taking votes, I'd prefer to see the 404s since I use the Redirection plugin and can already breakdown which page requests resulted in a 404. Although a Koko-specific 404 report would be even better - a report that lists all requests that resulted in a 404.