A single device on Android is hardly a choice--especially when the Nexus phones are NEVER the best hardware available. Even worse when the only choice is a super-sized phablet that will most certainly not appeal to many people.
I'm sorry but I find it frustrating that the best hardware and latest software are rarely found together on the same device on Android.
Motorola also seems pretty good about updates. The funny thing is, though, that lower end devices (Android One, budget Motorola devices) are likely to see M before the people paying 600$+ if they're not the Nexus 6. >_>;