I am getting ready to buy a quad core Apple refurbished (current model - May 2011) imac to use with my FCP Studio 7 (not FCP X). I am on a tight budget and my big question is whether the I7 upgrade chip is worth it? With the I7, will I be able to render faster in FCP? Will compressor speed up? How much faster is it for these and other video related functions. Thanks in advance!