Presumably, you'll be doing general purpose stuff with the macs you mentioned, or you would have asked which one handles (FCP, CS5, etc.) better. Likewise, if you had a necessary accessory that required, or would greatly benefit from USB 3 you wouldn't be making this inquiry.
I really don't think the 20% performance difference will necessarily result in noticeably faster real world usage. The tech world in general and Apple in particular has a bad habit of using artificial benchmarks in this regard: "New processor is 50% faster!" looks a lot better on a keynote slide than "Web pages load 3/10 of a second quicker!". The $300 difference can be invested in extended applecare, or a ram & SSD upgrade. These upgrades will make more of a performance difference than the different cpu's.
You mentioned the used MBP has high res antiglare, and presumably the 2012 refurb does not. If you require or prefer either the high res or the AG, it would probably make a bigger difference in your daily driving than the performance increase from sandy bridge to ivy bridge.
As for long term usage, does a 2009 C2D MBP really have an advantage over the 2008? Not really, both can still handle ordinary tasks reasonably well. I think the same will be said of the 2011 and 2012 models in a few years time.