I am planning to upgrade. I currently have a 2009 iMac with the i7 CPU and the standard video that came with it. I plan to sell this machine, which is in great shape. I'm looking at a new 27" iMac, and I'm wondering if there are any meaningful non-techy test reports you can point me to that show speed and other performance differences between the i5 and i7 CPUs available on the new machine and also that show the speed and performance differences between the two graphics chipsets available on the 27" iMac. I'd also appreciate helpful comments on the differences I might encounter in spec'ing these differences. I plan to go with an SSD drive, rather than a fusion drive. Thanks.