I do hope that, if we are looking at two screen sizes, that they'll be close to feature-equivalent. I'd hate if, say, you could only get the latest greatest features in a 5.7-inch model--that's 1.3 inches away from being an iPad mini, and it certainly won't fit in any clothing I own.
Moren: On the one hand, I don't feel that my iPhone 5's screen is particularly lacking. But I can also imagine changing that tune after actually using such a device. The key is making a larger screen that doesn't feel too large. I remember holding my friend's Motorola Droid X many years ago and comparing it to one of Star Trek's tricorders. True, the smartphone market is more mature than it was then. But I still don't think most people want to hold an iPad mini up to their heads. Will there be a bigger-screened iPhone? My gut says "Yes" pretty firmly, but my head is holding out for some level of moderation.
Chris Breen: Remember "ultrabooks"? Remember how Apple was doomed if it didn't follow the thought-leaders of the day and release one of these cheap, thin, underpowered laptops? Remember how that didn't happen? Instead, Apple released the product that made sense: the iPad. And in doing so, it helped sink the Ultrabook into obscurity.
The lesson learned is that Apple will only release a product because it thinks such a product is needed, not simply because everyone else is doing it. A bigger-screened iPhone could certainly be on the horizon, but with what purposes in mind? If it makes for a better reading or video experience, great. Likewise, a broader keyboard and a device more welcoming to text input would make for a useful smartphone. But to satisfy the challenge of a competitor's "mine's bigger than yours" boast? No way.
Dan Frakes: I've generally been of the opinion that the current iPhone (5/5s/5c) screen size is nearly perfect--large enough to make most things doable, but small enough that I can still reach any part of the screen with my thumb while holding the phone in one hand. However, a friend uses a Samsung Galaxy phone with a huge screen, and though he was initially skeptical of it (he got it for free from his company), overall he's grown to really like it. It turns out that, as huge as it is compared to my iPhone 5s, it still fits in his pants pocket (at least while he's standing up). But the major appeal, to him, is that the phone is big enough that he doesn't feel the need to buy a tablet.
That conversation got me thinking that maybe a larger screen isn't such a bad idea. When I think of the things I do most often on my iPad mini--reading (RSS, Instapaper, Kindle), browsing the Web, using social-media apps, triaging email, playing games, watching video, and writing--many of them would be nearly as good on, say, a 5.5-inch screen. Or at least good enough that, were I not a gadget geek who doesn't mind carrying multiple devices, I could be happy with that single device rather than an iPhone and an iPad.
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