This one always comes up, but no one ever thinks about how small it will make the keys. If you have a QWERTY keyboard, you MUST have 10 keys across. Look at that device and do a little thinking about what the keys would look like if there were 10 per row. If you can make a QWERTY keyboard on a device that narrow that is actually uasble, you sir are a better man than I.
Brother did it with one of their labelers ONCE and never again. I can absolutely FLY on the keyboard. Apparently consumers hated it, otherwise I'd expect to see it in more recent devices or in competitor's devices. Wouldn't work on DIAD III or IV, but V's form factor is perfect.
Now I can name two problems right off the bat:
1) If you're not a touch typist, you're gonna give a bigger WTF than when DIAD IV rolled out. Even if you are, you're still gonna give a big WTF.
2) With the staggared layout, I could place keys from the same row closer to each other since I had plenty of horizontal space. But between rows, there needs to be more separation to indicate that that's a seperate row. Meaning W can be pretty close to Q but needs to be far away from A.
I think if I had to actually roll this out en masse, I'd move the 0 to where the alt key is. (At least that's better than DIAD III with the 0 up top). Escape, Void, and whatever Delta is could be shorter but wider. I don't know how important period, slash, and dash are. The only time I can recall using any of them was DRing to "under mat" because period shares the key with M on DIAD IV and it yelled at me because period is not a valid place to DR. Period can also be handy when messaging the center. But I've never used slash or dash. I could see you using slash for one of the "half" addresses (123 1/2 Main St) when you have to key something not in EDD. Also, I might throw an enter key next to K, but the dead space is good too.