I've been trying to infer from benchmarks and reviews which configuration of Mac Pro gives the best "bang for the buck." 1. From what I've seen, the 6-core processor is a good compromise between high clock-speed while still giving those extra cores as needed. Seems like the 12-core chip is great if you have the applications that use all 12 cores, but for most people, the lower clock speed means the 6-core is a better option. 2. It also appears that the D500 Firepros are a pretty big upgrade from the D300s, but that the D700s aren't that big of an improvement over the D500s. Correct me if I'm wrong on that one. 3. Finally, I'm not sure if it's worth it to spend on extra PCIe storage. With 256GB internal, you could keep system files and probably a few current projects on the internal storage while getting external storage as needed for other things. Another wrinkle - I saw on Apple's support site a guide on how to replace the internal PCIe storage. Do you think there will be 3rd-party options to replace this in the future? If so, a few years down the road, a 1TB storage upgrade might be quite cheap. So, it seems like the most cost-effective setup might be the pre-configured $3999 model. Other thoughts?