I heartily endorse Apple refurb products to all my users and anyone else who is interested in buying a Mac. I have purchased numerous refurbs over the years, and other than not having the retail packaging, they have all been as new as I could imagine from a cosmetic as well as a functional standpoint.
If you're really living right, you can end up with a "courtesy upgrade," which is a standard spec model that might typically have 1G of RAM, which the prior owner had put an extra gig of RAM in, for example. They pass a lot of this stuff along, and if you get it, well, it's a "courtesy upgrade".....
MacDann