So the base 13" rMBP comes with a 2.5GHz dual-core Intel Core i5 processor. My late 2009 iMac has a 2.66 GHz Quad Core Intel "Core i5" I5-750. Admitting layman knowledge here ... does that mean my 3 year old iMac has a better processor than the 2012 13" rMBP? Or am I missing something regarding L2 cache or the chipset that makes the direct comparison not valid? Thanks.