Going to piggyback off this thread...
For the past few weeks, I've been using an iPhone 5S for work and iOS 9 is still pretty abysmal, in my opinion.
We've had discussions about similar issues in the past so happy to offer some suggestions/counter points where they might be applicable. I'll also reiterate here that I'm not necessarily disagreeing with many of your points or claiming an iOS solution is better but rather just offering some additional insight from someone who's been using iOS consistently for quite a while now.
I can't stress how much I'm bothered by a lack of consistent back button or at least a consistent back-experience. I'm still seeing a lot of upper-left, upper-right, center of screen, etc. type of experience to go back, and it's dreadful. Horribly inconsistent where you have to look for and be aware of the way to navigate back. It slows down the overall experience of navigating through iOS. We all know Apple will never (ie. highly unlikely) have a dedicated back button, and I think that's a real shame. Especially because there is clearly bezel space for it.
There really isn't an argument to be made here--if you prefer the back button, you won't find the exact same functionality on iOS. I know you're aware of the swipe from the left edge to go back (and yes that it's not universally applied) but I find a significant portion of my apps do utilize it, so my only advice is try it first (all apps will likely have a secondary button as well). Using a 5S you are also missing out on an additional feature that's available on the 6s/6s+, the deep press to switch apps. So, if you swipe from the left, if an app supports it, will take you to your last page. If you press slightly harder, it will pull up the stacks of apps in the app switch, with the last app you utilized on top. Also, if you access another app from a link, there will be the option to return to the app in the top left corner (yes, agree that it's not an ideal location in regards to reachability). Needless to say, I can navigate quite well without have to hit any 'back' buttons in most cases.
Also, it's been a while since I've used iOS (at least half a year) and I've already forgotten how rigid iOS is. The grid is just so goddamn boring. I'll take just the apps I want and widgets on the home screen any day. BTW, widgets in the pull down, sounds organized in theory, but I find it more disorganized. I rather scroll left/right through paginated home screens where there are clear breaks as to where my widgets are than a forever up/down scrolling through a "list" of widgets. Speaking of the pull-down, it's a shame we have to scroll left/right to see widgets or notifications. If I want to see my widgets but I left it on the Notification side, I have to scroll left first; if I want to see my notifications but left it on my Widgets side, I have to scroll right. Extra steps because iOS can't be more dynamic than a grid of apps.
No disagreement regarding the grid and especially the inability to at least arrange icons in free form--the 'snap to the top' is ridiculous. FWIW, I heard it explained that one of the reasons it hasn't been changed is the Apple's philosophy is that the home screen is just an access point, that your time is meant to be spent in apps themselves. Regardless, I'd like to see a bit more flexibility on the home screen as well.
The widgets implementations on either platform come down to a matter of preference. I like the iOS implementation and the ability to access them at anytime, from within any app but certainly understand you preference as well. The extra step to switch between widgets and notifications? That seems a little nitpicky. Doesn't it require 2 pull down motions to expand the quick settings on the Android notification shade?
Lastly, I still hate the Settings menu. It's still, in my opinion, disorganized and difficult to find things. Maybe I'm just not used to it, but I much prefer the way TouchWiz does it. It's color-coded and there are options to put your most accessed settings at the top. Convenient. Also, I feel things are disconnected. For example, Control Center... why can't I go directly into say WiFi settings if I want to? Even if it's not as intuitive as Android where you can long-press the WiFi button to go directly into WiFi settings, why not a Settings shortcut button somewhere? At least that. And I'll continue pointing out the one thing I've always pointed out ever since the inception of Control Center; why not allow us to choose what quick settings we want? I don't need AirDrop there. I don't need a calculator there. Nor a timer there. I'd love an icon that'll take me to the full Settings menu though.
Won't disagree regarding having the ability to customize Control Center, nor adding additional functionality with either a long press or hey, use 3D Touch now. There are however some workarounds--i.e. i use a
Launcher widget located near the top of the top pull down shade that allows me to add shortcuts to pretty much anythings. I use it daily to quickly access things like Wifi settings or 1Password (immensely useful if the app hasn't integrated an extension for it). Basically, it is mimicking how you'd access these settings from the Android quick settings pulldown.
Other tidbits...
Safari is still a bit of a drag to use compared to Chrome. For example, switching between tabs requires 2-3 steps. Chrome is just one swipe left or one swipe right if the tab you want is next. Also, I know this is preference, but I still hate the way Safari scrolls. Tap to go back to the top, always a lovely feature.
Well, as Safari uses those motions to move back or forward a page, can't really duplicate it. Do you have to use a button to go back or forward in Chrome on Android phones (sorry, been a little while, gave my only Android phone to a friend so I can't test it)? I also alway found accessing bookmarks in Chrome to be a bit more cumbersome since you had to use the hamburger menu in the top right corner, rather an icon directly on the page. Won't disagree about scrolling--I find it too slow for my preference as well though like you, I love the top at the top to instant return to the top of a page.
iOS 9 is buttery smooth. Fingerprint sensor also fast. Faster than S6 for sure and this is a 5S.
Who says iOS doesn't come with bloat? I have a folder of "Extras" full of pages of Apple related bloat I don't want nor plan to use.
All phones have bloat, for certain. At least iPhones don't have to deal with carrier stuff.
Mail experience is still pretty good, though I definitely have bones to pick. Nothing worth getting into.
I like Mail.app as well but primarily now use Outlook--even better experience, IMO, highly recommend it. I also use Sunrise Calendar. Who'd have guessed Microsoft would offer arguably better experiences on the iPhone.
😛
The keyboard finally shows upper case lettering! Miracle.
Count me as one who prefers the iOS keyboard experience, at least for tap typing. I just wish they'd implement a 'swipe' options as choosing a third party solution means I lose out on the 3D Touch cursor option (another awesome feature, though sadly not available on anything other than the 6s/6s+).
Still have yet to dive into Apple Maps or the like, but I do hope it's better than I last remembered.
Don't bother. Yes, it's improved and while I do think it offers at least as good a navigation experience as Google Maps
on the iPhone, overall it still can't match Google Maps, especially when it comes to POI.
There's probably more I could say but I'll leave it at that. Those that know me will not find anything unfamiliar here. In short, iOS still has some ways to go in my opinion before it can live up to the world's most advanced mobile operating system. It still just doesn't feel very advanced, sadly.
EDIT: I still have to update the OS via WiFi only? Wut! C'mon.
Considering some updates are around 1.5 GB, I can't really fault them for that precaution.