Depressed at the state of the market...
I have a Nokia Lumia 1020 on 8.1 - and a fantastic phone it is. WinPho 8.1 is a great OS with the apps and features I need - Cortana works well, the 41MP camera is great, even if the CPU has barely enough grunt to drive it. But its getting older and I'm probably going to want a replacement. But what to do?
Apple - I had an iPhone 3G and a 4 (plus I have a 4S from work). Would I buy one now? Good gracious they're massively expensive for what they are. Their hardware is nothing special (My 3 year old Lumia has a better camera for one) and iOS isn't nearly as slick as it used to be. Not to mention, they have a real habit of stitching up customers with older devices.
Android - I've tried it, and tried to like it. Trouble is, for all its flexibility it's too fiddly and inconsistent. Not to mention, there's always rumblings about lack of vendor support and security issues. Let's also remember that Android is a product of Google - the true, world-dominating data-monger.
Windows 10 Mobile - MS don't know what to do. It needs backing or killing off, not this limbo situation. Again, great hardware at good prices - but the declining support and poor quality release code, caused as much by indifference by MS as much as it is the market, will be its undoing. A 950 or the rumoured 1050 or Surface Phone might be nice, but is it worth investing in a device on a platform that might disappear?
While the hardware is moving forward nicely, at the OS, it's stagnated into too narrow a band - essentially a duopoly of Droid or iOS - MS had a chance, but being late to the game and mismanaging it after that has left its future hanging on the precipice. Not a particularly attractive choice in any case.