I have the iPhone 7 Plus as well as the Android phones in my signature. Regarding the loss of the headphone jack, in a bubble of using just my iPhone, it turned out to be okay. Not ideal, just okay. I use the adapter if my Bluetooth headphones aren't charged. I try to keep them charged now.
What does eat at me a little is when I listen to even the less than stellar quality streaming music from Apple Music on my HTC 10 with its excellent DAC and use even my cheap wired headset. There IS a difference. Music is more "alive" on my HTC with better definition between instrument sounds and more nuances in the vocals. With my HTC hi res earbuds it's a knockout.
If people have never tried a comparison, they likely won't know or care what they are missing. Many people with damaged hearing might not care, either. Even with my tinnitus I can appreciate the difference and I value my HTC 10. And desire a good DAC when possible, which is why I'm pretty cheesed off at these arbitrary regional differences that have LG dictating that certain markets, like the US, won't get the high end DAC. Wth.
Lol, didn't know about mouse support until your post so obviously that's never impacted my choice before and likely won't. I would appreciate it on a tablet, however.
I'm not a "power user" but even I can appreciate and have availed myself of file system access.
Split screen multitasking is convenient but not a must have for me at the moment.
I HATE HATE HATE how "back" is implemented on iOS. It's more of a problem on iPad when sometimes I'm trying to actually slide an onscreen control sideways like on You Tube. Or scroll sideways on an onscreen interface. I so often end up going back, instead and losing my place. I'd rather have a dedicated button, virtual or capacitive, OFF of the touch screen to avoid the accidental sliding back to a previous screen.
I love widgets but I found myself paring back on them. I am okay with how iOS implements a limited version of widgets all on one page.
As someone who has nearly filled my 256 GB IPhone up already, lol, I sure would appreciate SD card expansion. It IS nice to be able to move my card between my Android phones and have easy access to my stuff that way. I would like a mix of both generous onboard storage and an SD card option.
Google oddly enough, is very un-Android with its 32 GB start point and NO expandable storage.
I can see Apple going in a good direction, slowly but surely. I'd like them to keep increasing audio quality (and call quality--seems better on my Androids) and studying the Androids and matching or besting them feature for feature. Especially if they keep charging premium prices.
With Android, I'd like to see them pursue some sort of strategy to keep people up to date for security patches and continue to implement strategies to improve the quality of apps and weed out malware and invasive adware.
Where both iOS and Android seem to be converging is in the number of times their apps crash. I have had an annoying number of crashes to home screen on my iOS 10 devices. I've got my iPhone and my iPad mini 2 up to date on 10.2.1 and still have more crashes than I'm used to having on an iOS device.