This looks like super cool hardware. The hinge in particular!

I think hardware and software made by the same company can have big advantages.

For me personally, I don't really see much use case for something this size the same way I don't see much use case for an iPad. If I have a lot to do, I'll use my laptop. If it's something quick, I'll use my phone. I don't have much need for an in between currently. I'm sure there are use cases for this that I haven't thought about, though.

And not to say I wouldn't want one, looks great!

EDIT: As a phone replacement (new product video for Surface Duo just shown), this is even more interesting!