Naturally, there's going to be some hesitation by those who've been used to the 3.5-inch or 4.0-inch size of all previous generations of the iPhone, but the 4.7-inch model is still reasonable enough that most users should easily get used to the new size. At 6.9mm, it's thinner than the 5s (7.6mm), and its curved sides bring a sleek look that should still be plenty comfortable for most traditional iPhone fans. I had no problem gripping the iPhone 6, and it felt right at home in my palms. However, it's not going to be the smallest phone of its size: Last year's 4.7-inch Moto X, for instance, is 1.7mm narrower and nearly 9mm shorter than the iPhone 6. That means its curved edges and thin body will be the saving grace for most; the aforementioned X is 10.4mm thick, over 3.5mm beefier than Apple's version.
The iPhone 6 has a 1,334x750 resolution, which translates into a pixel density of 326ppi -- if you're keeping count, that's exactly the same as the iPhone 5s, just adjusted for a larger size. So if you were perfectly happy with the display quality on the 5s, I'd wager that you'll have a very similar experience on the 6. That said, the 6 Plus, with its 5.5-inch panel, comes with a 1,920x1,080 resolution for 401ppi density, so it's certainly better from a technical standpoint. I'm looking forward to putting both phones through their paces, but in a brief hands-on, the difference seemed marginal enough that it likely won't be a deciding factor for anyone trying to choose between the two sizes.
Most of the buttons are in the same location as previous iPhones, but the power button has moved from the top side to the right. Apple felt this was necessary given the bigger size. This makes the most sense on the Plus, since it would be quite difficult to reach if it were still in its old location; on the smaller 6, I don't think it was essential -- I've used plenty of similar-sized phones with the button on the top -- but this will likely be much more comfortable for most people used to the 4-inch iPhones. A volume rocker and mute switch are on the left side, while the 3.5mm headphone jack, lightning connector port and mic/speaker setup are on the bottom. The top side? Now bare and smooth.
The aluminum back's layout is very similar to earlier phones -- the camera and TrueTone flash are on the top left corner, with only a stainless steel logo and FCC information further down -- but the camera module sticks out from the chassis (necessitated by the iPhone's additional thinness) and the entire back is the same color, with the exception of a couple lines that dissect the top and bottom sections.
In direct contrast to the sharp design of the 5 and 5s, Apple has chosen to go back to round. The chamfered edges of the 5 and 5s are gone, replaced by a pane of 2.5D glass (which Apple refers to as "ion-strengthened") that slightly curves down to meet with the bubble-curved edges. The choice is to ensure users can use gestures and swipe to their heart's content -- say, with the keyboard -- won't be distracted or interrupted by the phone's design. In other words, this is supposed to be more of a pebble-like experience on top.
Of course, one of the biggest and most anticipated features in the iPhone 6 series is NFC (near-field communication). In a nutshell, this makes it possible for Apple Pay, a wireless payment method that's being embraced by hundreds of thousands of merchants and a large handful of popular banks.
It comes with an 8MP camera, but if you haven't figured this out by now, Apple doesn't really care so much about specific resolution as it does all of the other stuff behind the scenes.