Didn't comment on this early because I was in a hurry.
The large fan, the massive heatsink, and the liquid metal make it clear that cooling wasn't an afterthought like it felt on the PS4.
I thought the base was well thought out before (there are good logistical reasons for the design). But it managed to be even better.
(And funnily enough some people are picking on MS a bit more with their un-removable stand, which I didn't expect).
The SSD expansion slot is as easy as it could have been.
The PS4 had a pleasant design, but this makes the PS4's design feel like a last minute thing.
They took some different choices than MS, but its hard to deny both consoles are really well designed.