Hello there, i'm looking to change my iMac 20'' 2.0ghz CD for a refurb 24'' 2.4ghz C2D. I just want to know if ther is a BIG difference in speed between mid 2007 and early 2008. I know that the bus and ram are faster and also that the processor got 6mb l2 vs 4mb...but in REAL world...will i see a BIG difference. Keep in mind that the refurb is 1299 and i'm upgrading from a 2.0ghz CD !!! Also that i'm gonna put 4gb in this baby. Thanks to all !!!