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it looks like the space was used instead for cooling. That "hulking great fan". That seems to be the other reason for sticking with this form-factor as opposed to going smaller (the other being easy swap-in-ability when replacing previous models in datacentres and other tight spaces). I'm hoping for a machine with the highest cpu option that won't be throttled back to oblivion if you actually ask it to do some work for more than a few seconds at a time. It's looking hopeful, but hoping for a bit more corroboration than one reviewer's informal ffmpeg test. Almost ready to fork out. It looks like the Mac I've wanted for some time.