Okay, first up is a disclaimer. I'm still getting my feet wet with REST so this might be totally wrong. Proceed at your own risk.
When looking at your collection from these other perspectives (recent = time, status = enabled/disabled/featured/etc), these other perspectives become controllers.
This returns some default timespan of recent articles.
This returns articles from the past 45 days.
Or maybe you just take additional parameters in to your regular #show method.
This might behave just like the #recent/45 example above.
I highly recommend looking at the articles on wikipedia  and RestWiki  to understand how to apply REST principles. The REST approach will likely result in more controllers, but each controller will be much simpler to implement and test. If you are still stuck in the mode that says there is a 1:1 relationship between controllers and models then you might be in for a rough ride.