But they are different in that they _don't_ run the same software -- freudling's point number 3 is just plain wrong.
The iPhone often runs similar, but less functional versions of iPad apps. And some iPad apps aren't available at all on the iPhone because the screen is so small that it isn't even worth trying to make the app work on it.
They are quite similar, but the screen size is such a factor that they divide into different categories by the apps they are able to run.
Well... I'm not a developer, so I can't say for certain, but my guess is that where different versions of apps exist for the iPad and iPhone, like Pages for iPad and Pages for iPhone, or Calendar for iPad and Calendar for iPhone, more than half of their code is the same. And in many cases, apps for iPhone and iPad are even more closely related to each other -- some iPad apps are almost the same as their iPhone versions except for cosmetic differences to adjust for the different screen sizes. So you just can't make a blanket statement that iPad and iPhone don't run the same software. In many cases, they do. And even in cases where the iPad and iPhone versions of an app are distinctly different from each other, they clearly belong in the same family, especially when compared to desktop/laptop apps.
So to make an analogy, iPad and iPhone apps are like wolfs and dogs, while desktop/laptop apps are cats
. What you are doing is focusing on a difference between dogs and wolves -- that one is domesticated and one is not -- and insisting that everyone must think of that distinction as the most important.
A biologist is going to say that dogs and wolves are pretty much the same, and they can even interbreed. He's not going to place as much importance on the domestication factor. But to a farmer, a dog is a trusted helper, and a wolf is a dangerous predator. A farmer might get understandably upset if he thinks a biologist is treating dogs and wolves as variants of the same category. A biologist would be exasperated at the farmer's short-sightedness in insisting that dogs and wolves are different when they obviously share so many characteristics.
It's all a matter of perspective, is what I'm trying to say.
But the MBA and Mac Pro are still in different categories (or subcategories, if you prefer). One is an ultraportable laptop and the other is a desktop. Sure, they both belong to the category of "personal computer," but that's too vague and general. These are two highly distinct product categories with their own unique advantages and disadvantages, despite their obvious similarities
Well, but from a software development perspective, nobody makes a "MacBook Air" app, or a "Mac Pro" app. So in that sense, the distinctions among various types of desktop/laptop aren't as important as the distinctions among different-sized multi-touch devices, as you also mentioned. And it is because of this that I do feel suspicious of the "tweener" size tablet. Unlike freudling, I'm not going to say tweeners are destined to fail, but since the size difference between an iPhone and iPad does necessitate, for most apps, a separately designed UI for that particular size device, then there is a likelihood that the tweener tablet also needs its own UI, different from both the iPad and the iPhone. If Apple and the devs don't provide such an optimized UI for the tweener, then the user experience may not be as good as either the iPhone or the iPad. And I do think this is what freudling is claiming about the Nexus 7, that the user experience is inferior because the UI is not optimized for it, but he's going about it in an antagonistic and needlessly argumentative way.