It's not a PC-style mini-tower - really, it isn't. We've spent some time with Xbox Series X at Microsoft's Redmond campus and even put the actual system side-by-side with an Xbox One X - and while it's clear that Microsoft has radically revamped the console form factor, it is still a living room friendly design. It's just somewhat different and definitely somewhat portlier than the kind of gaming box you may be used to. Crucially, it's still very much a console.
The design of the Series X is essentially a factor of the performance target, a machine designed to operate at fixed clocks at what are - for a home console at least - unprecedented frequencies. A console has never run its CPU component at 3.8GHz before. We've never seen a fixed design games machine run its GPU at clock speeds that match the kind of frequencies we've seen in a discrete PC graphics card. On top of that is another key design goal - to back away from fluctuating 'boost clocks' seen in PC parts and mobile devices and instead deliver high-end performance with rock solid consistency.
So, to kick off with, here's a new Digital Foundry Direct episode recently shot in the US, where myself and colleague John Linneman discuss our impressions of the Series X hardware itself, roll out all of the Xbox One X form-factor comparisons you need and come to the startling conclusion that Series X is indeed rather similar to two GameCubes stuck together. OK, so we had to strap on a couple of GBA Players to get broadly equivalent height, but you get the idea.