So, I've watched part three of the XBox One Tablet Build.
First: Nice Build.
But since you've asked, here my thoughts about what I'd have made different.
Tablet or Laptop:
I'd probably would have made it into a laptop form factor simply because I don't really like to play with a controller, so I'd have bought a adapter to play with a mouse and keyboard.
With this in mind, I would have tried to use a laptop or a different slim keyboard to make the unit as slim as possible.
With this said, there are a couple things I'd made different regardless if it's a tablet or a laptop.
Power connector and supply:
I'd have checked if I couldn't tap into one power supply to feed the other electronic device, possibly choosing a display that already requests a certain voltage/amperage that the Xbox PSU can output.
Also, I'd have sunken the power supply mains connector plain with the case.
Bluray Drive:
AFAIR the Xbox 360 had to be used with the drive that came with the unit but since it's a new model I'd have tried to use a slimline bluray drive from a laptop instead of the factory one.
Drive Connections:
Before cutting up the connector and extending it, I'd have looked if I can find a SATA cable with the (kind of) right lenght, possibly in my cable bin.
The last Layer:
Instead of leaving the layers more or less plain, I'd have made a mould and made a layer out of vacuum formed plexiglass. I guess, it wouldn't be an option for the show, since it takes time to set everything up to make the heating and vacuum forming rig, but it would have been an interesting thing to show on air.
These are my thoughts about what I'd have made different.