We're talking about the Unibody vs the Aluminum, right?
Well, aside from DDR3 RAM, Buttonless Glass trackpad, Sturdier Unibody, High Gloss display, updated dual graphics mode with the 9xxx series GeForce.. there might be more, but I think that's pretty much everything. If you don't need any of those, then I think you'll be perfectly fine with a refurb of last gen's model. I love mine. I would like to have a Unibody, but I don't feel like I have an inferior machine in any way.