I have a 7+ on 10.1.1 jailbroken, matte black
Tried a silver/white 8 64gb, and it actually had a nice screen without major flaws, and seamless glass back, but the front wasn't as seamless and the lightning plug wasn't snug (across different lightning cables)
I returned it (sad to return a good screen device, as they seem rare), but ultimately because I didn't want a stock, buggy OS and to play the wait game with my money.
x.0 on new hardware, in my experience, is typically way more buggy and introduces new hardware-specific bugs vs. older hardware on same x.0 (that has been public beta tested for months w/ feedback).
It may also be that iOS 11 is more iPad-centric, but 11.0 GM on my 12.9 gen 2 has been working REALLY well and I'm quite pleased with it, even though its not perfect.
Couldn't justify same form 4th time, for $750 after tax. The glass back is grippy ,but the sides are still slippery and I'd still throw it in a case and then the physical differences would disappear.
The camera differences seemed there, especially a faster shutter across the board, but sometimes not as good as 7+ either, I wasn't as wow'd as I thought I'd be. The speakers seem clearer too, but I don't find my 7+ speakers to be crap at all. And without side by side, I'm caring even less.
the battery life appeared quite impressive for a 4.7" tho!
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I just dunno what I'm going to do, but luckily SE and 7+ is still an amazing combo for me.
Could try an 8+ but I dunno if I want to go 128->64, and have two pluses, since I won't sell or offload 7+ until theres another jailbreak to migrate into the new hardware 100% with, and then if I get the overkill 256 its $950, which is nearing $999 for X at 64GB. I also don't mind added heft to 8 ,since I've skipped 4.7" for a solid 3 years now after brief dabbling, but the added heft of 8+ for its size is something I'm not personally thrilled about. 7+ feels better to me,
X seems weak with FaceID/no TouchID (a balance I don't care for, on paper)/the price tag, and depreciation next year will be MAJOR when X-2 or whatever comes out, so I'd only get an X if I knew I'd be holding onto it for a long while.
And if I did, I'd be tempted to cover up FaceID with tape, and go old school pin passcode method, but then its a regression from 7+ and SE with TouchID, and paying $1000+ mostly for trimmed bezels and an OLED panel.
Never been more confused, upgrade path wise, but not fretting either.
Before people say- embrace FaceID its the future, its my prerogative to embrace what I want to and what I don't, just as its yours to embrace it with arms wide open and I equally respect that.
My skepticism surely isn't unique or limited to me
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Good iOS lessons- don't sell your old device until you're sure you're happy with the new one and its build and everything, or you'll screw yourself.
Also keep old device on previous iOS while trying new device, that way if you don't like new OS, you got the old one. If you do, you can just OTA it.
If you have regrets, and still have your old device, then by all means, RETURN it.
No reason to live with *regret* of a $700+ device that shares many features of the previous iteration, and past 3 designs.