On medium sized sites, keeping track with the full site activity is nearly impossible:
If you read only question posting order; you miss any new (and frequently good) answers to old questions
If you try to read in "active" order (or the site RSS feed which follows that order), 90% if not more of posts that appear there are listed because of some truly insignificant edit (1 new tag, <10 characters edit) and/or Community user bumping the post.
This means that on sites of a certain size (such as SciFi.SE) reading the active updates/RSS feed is basically not feasible.
Can there please be a third option added for sorting the questions (don't care if it's web or RSS); that shows the questions in active update order - the same as today's RSS - BUT ignored the "trivial" activity (small edits, tag-only edits, community user bumps).
The lack of this functionality poses downside to both the site in general since less community moderation happens on new content for older questions - as well as to individual users who are missing out on reading potentially great content posted on old questions.
As a easier to implement alternative, a more restricted version of it would be showing only "new post" activity (e.g. questions that have new answers only; ignore ALL edits/bumps).