"kind of a scaled-up smartphone – which is a bizarre produc, in our view."
Obviously their view is not shared by many others. Older users tend to need eyeglasses and/or larger type - which is not too easy if the screen is as small as Apple's smartphone.
Equally, unless you are wearing a trench coat, the Apple tablet is too large to fit in a pocket and is a bit heavy in the hand.
The mid-size tablet is the best of both worlds: a larger screen for those who need it; small enough to fit a suit breast pocket and even hand carry for a period of time. Using either a wired headset or a Bluetooth connected device, voice communications can be conveniently achieved. The larger case permits a better speaker and bigger batteries, as well as providing more real estate for external connections.
My company has just complete a Test of Concept where service/production manuals for complex numerically controlled industrial machines. The manuals were made available on three sizes of screens - smartphone, 7 inch and 10 inch. There were sufficient pad/tablets to let the test subjects all choose identical units. One condition was they were to use each size at least twice.
The most popular size proved to be the 7 inch screen based upon usage.
As a private project I used 7 inch screens in my home to provide, primarily, dictionary services - my wife's mother tongue is way different to mine - and were affixed to a wall in the kitchen and portable elsewhere.
The kitchen unit was also used to access recipes from the InterNet and the others for miscellaneous browsing including newspaper sites.
It is my experience that a 7 inch screen is very satisfactory for most uses, commercial or otherwise and doesn't support Cooks proclamation, which is somewhat bizarre in itself. Now we will have to wait and see what the market says.