It is completely a personal preference, but I think you can get closer to a "daily driver" experience with a beheaded laptop. Two reasons: 1) you'll get better performance. This would be a moot point if you were using a Framework motherboard (or the Steam board was more widely available). 2) form factor. I would prefer to carry around a thinner slate computer over a thicker lunchbox computer. This is just personal preference.

For most people though, I think adapting an existing laptop is an easier project than what you've been able to accomplish. Don't get me wrong - I'm impressed. And I also really like the idea of a headless computer with AR glasses as the display. I think it's a use-case that needs to be taken seriously.