For me, I settled for the slide-keyboard form factor with N810/N900, but I much prefer clamshell.ED, sounds like your next project should be a phone with slide keyboard.
I would buy it.
If you're trying to avoid the headset, you could just throw mic & speakers in a reasonable place on the outside of the case.
My suggestion for the next project is an Atom-based CPU board upgrade that can compete with the GPD WIN.
OMAP5 is already obsolete - the main reason I'm still planning to get a Pyra despite this is because there's nothing better, but if GPD WIN had a modem...
Also, if the upgrades are delayed much, I'm afraid the current non-upgradable system won't have much value left: in a year or two, people will probably expect USB-C and such.
Frankly, I already value the upgradability at near zero due to the lack of camera, but that's another one of those things no competition seems to be providing (yet).