I switched to the flagship 2014 Moto X in October 2014. I got the material design update (iirc lollipop) in march 2015 and by then it was slow. The battery life was terrible. The camera was worse than the old windows phone despite the superior resolution.
Having a less than one year old unusable flagship sucksss. I got the iPhone 6s at launch and was blown away by the battery life, and the speed. I'm no Apple fanboy (as my post history proves), but iPhone is hard to beat. I'm thinking of getting an iPhone 8, not because there's anything wrong with my phone now, but because I want a shiny new toy. (and now I'm starting to rethink if its a wise decision...)
I've been burned by android and I just don't feel like I can trust the device to still work in a year. Kind of like the worst of Windows devices in the mid 2000s.