Coming from an iPhone 4S, the 6 is quite a big change. The screen is huge enough that it makes one handed operation more difficult, but at least for my hands it just remains possible if you lay the phone flat in the palm of your hand. And for this position I highly recommend a leather case, without a case I would worry that the phone would slip from my hand. And if you require a firmer grip, a double tap on the home button will work well enough to bring the elements into reach. The problem is ironically the lower far corner, which I can only just reach with my thumb. This means that if your hand is smaller than the average male hand, you really should check in person if the 6 is not too large for you.
The screen on the other hand sufficiently compensates for these problems: you can see a lot more ( or if your eyesight is fading, you can activate a scaling mode to have a permanent zoom mode). It especially makes writing easier, with the larger keyboard targets, and should enable even fat fingers to no longer need landscape mode. It is an adjustment to get used to the new spacing coming from a previous iPhone, but while you are learning, autocorrect works quite well in guessing what you actually meant to write. The larger screen is especially welcome for watching videos, where the improved brilliance and viewing angles of the display also get to shine.
Even with the larger dimensions, the 6 is a tiny bit lighter than a 4S, and still fits most pockets easily: only specifically tailored phone pockets will be too small.
Others [1] have written extensively about the new phone, so here are just my highlights coming from a 4S:
- Touch ID is a great win for security and convenience. My recommendation is to let 1Password generate you pronounceable password of about 16 letters, use that password for about a month without the sensor so that you have properly learned it, and then activate Touch ID.
- the camera is brilliant, the new manual controls very welcome, and it is just so much faster to start up and to focus.
- I really like the improvements to typing: the suggestions in the bar above the keyboard are good often enough to improve typing speed, especially one-handed, and the speech recognition is a good deal better, and now supports Dutch as well.
- AnandTech has the technical details, John Gruber provides detailed insight into its uses, and Rene Ritchie has a detailed iOS 8 review ↩