Page 5 - Look and Feel
One of the strengths of this phone is that everything on the screen is tastefully designed. The lock screen graphics are gorgeous. The 4.7-inch display is bright and crisp. The icons are well designed. Text, for example, on the phone dialer is large and easy to read. The black and grey theme is low key and mature. I've included lots of screen shots so you get a feel for all that.
Best of all, when a Setting is changed, the explanatory text also changes to reflect the sense of the current setting. (This is a Fire OS feature.) That's something Apple probably didn't have room for on its 3.5 and 4.0 inch displays. Apple should add that to iOS.
The Silk browser, unlike Mobile Safari, always shows the full URL and, unlike Safari, has a sane and sensible "Find in page" menu item that is vastly superior to Apple's. Support for the 802.11ac Wi-Fi protocol, something the iPhone 5s doesn't have, seemed to bring up web pages just a tad faster on my home's 5 GHz Wi-Fi network.
SIlk Browser shows full URL.
Overall, I prefer the look of the Fire OS 3.5 to iOS 7. The home page icons are spaced farther apart and the annotations in the Settings give themselves more room for explanation. However, my sense is that iOS provides finer control and more extensive settings overall, especially with apps like email.
In general, iOS tends to be sparse with surfacing information that it certainly knows about. One of the things I appreciate about Android and Fire OS is that useful information tends to be judiciously revealed rather than suppressed for the sake of simplicity. A good example is the email app which shows the user's account name and also leaves the full email address in plain sight after you select it on the "To:" line so you can check for a mistake. Lots of people have one name but multiple email addresses, and selecting the right one can often be important.
Next: Miscellaneous Observations