What would it take for you to come back to a Windows Mobile? -> Simple; release true flagship hardware NOW!
Where are the ultimate mobile devices/cellular PCs promised by Microsoft? 2018 will be too late, everyone will have jump ship and move to a different ecosystems (which is harder than simply changing phone)
I am still in, with my 950 XL and Band2, but my MS ****** loyalty is getting seriously eroded by the lack of consumer commitment of MS towards Consumer market (appart for XbOX related product).
Get more hardware supporting Windows 10 mobile... or announce now a soon(tm) to be release category defining cellular PC (soon = 2017, not 2020!). Rumours of Windows on ARM for Cloud tablets/book are not enough, I need a category defining "pocketable" device.
Windows 10 Mobile is a great OS, but there is no hardware to run in onto...
I would love to recommend Windows Phone, but when people ask me what they can buy, my answer is simple, you can't buy it! (same for the band 2, they like it, they would like to get one, but they can't buy it) hence they go to Android or iOS...
The 950/950XL are nice phones, but nearly 2 years old by now!
There are no "sexy" flagship phones on the market running Windows 10.
Launch a S8(+) with windows 10 mobile OS (not apps) and that would grab people attention once again...
App Gap? I have all the apps I need in the windows store, so not so much of an issue for me.
How long before I jump ship... soon(tm)!