New MacBook looks beautiful and I've been thinking of selling my iMac for a while now for a laptop. Just wondering if I would notice any significant improvements in speed/performance with the new MacBook vs my old iMac. My current iMac: 2011 iMac - 27" - 3.1GHz i5 Model with 1TB and 16GB Ram Its been running a little slow the last year or so. I'm not even sure what I could get for it if I sold it. Or where the best place to sell it is. Advice is welcomed!