Quite a lot has been made of this machine's supposed lack of expandability relative to its predecessor — which seems to mostly mean a lack of PCIe slots. It's worth noting that there are use cases for which the new Mac Pro is far more usefully expandable than the old one. Folks have pointed out that the old Mac Pro can be loaded with with a couple of modern GPUs, and will perform decently. Some has asked why, if that's true, people are so excited about the new Mac Pro. Here's why. If you're building out a machine for, say, DaVinci Resolve, and you start with two double-height GPUs... congratulations, you now get to decide whether you want a video I/O interface or a RAID controller... because you've only got one slot left. When you opt for the video I/O interface (because Resolve is unusable for professional grading without real video monitoring), you're left with a machine that has no external storage interface faster than FW800 (~80 MB/s). The only real way around this problem on the old Mac Pro was to buy a PCIe expansion chassis, but those make Thunderbolt to PCIe enclosures look cheap, they're bulky, they have awkward cabling, etc. None of this is an issue with the new Mac Pro. You've got two fast GPUs on board. Video I/O is trivially provided by a Thunderbolt device, and you're still left with lots of Thunderbolt ports (each ~25x as fast as FireWire 800) to connect to a RAID, a Fibre Channel or 10 GbE interface, or practically anything else. The new Mac Pro accommodates this expansion-heavy use case much better than any Mac Apple has ever made. For added bonus points the machine itself is tiny (which can matter for some video customers, who might want a high-powered system they can take on location), and because your high-priced peripherals are external, they're not locked up in a single workstation — a facility can very easily move them between systems (including laptops!) based on where they're most useful. So, for instance, with a RedRocket card in an external Thunderbolt enclosure, you can use it in a color grading suite with a new Mac Pro while grading R3D footage one day, and then the next day, if the suite is being used to grade Alexa footage, use the RedRocket with a MacBook Pro to crank through some transcoding work. Given the price of some of this pro video gear (a RedRocket card is $4750), this is a very useful capability.