I've been an Apple refurb customer for years now, purchasing everything from iPods, Airport wireless devices, and even a desktop for up to hundreds of dollars less from their online "Apple Certified, good as new" section, all without any issues. From all I could tell, the refurbished products purchased were either brand new and returned, or as close as one could get to new, with all the same warranty coverage as a brand new device...
If you're on the hunt for a refurbed model Apple computer, iPad, iPod, Mac Mini, iMac, or Apple TV, but the specific model you're hoping for isn't in stock online, you'll want to setup a notification via the Apple Refurbished Stock Checker.
Enter an email you want to be contacted at (I used my designated "for signups only" Outlook.com email address for this purpose) and choose the specific device you're searching for, and the site will send an email notification immediately after the product returns into stock on the Apple site, making bargain hunting all that much easier!
(Image: Gregory Han)