Decisions decisions.... Which is a better deal: the previous gen REFURB imac, 20", 2.16 c2d processor, ATI Radeon X1600 with 128MB GDDR3 memory for $1,099 -or- new gen NEW imac 20", 2.0 c2d processor, ATI radeon HD2400 XT with 128 mb memory. $1,199. ALL OTHER SPECS BEING EQUAL: WHICH SHOULD I GET? WHY?