My initial solution...
I reverted my 1520 to 8.1 and dedicated it as a camera. I feel there were a lot of advantages to this reversion, not least of which is less processing load for camera. I also had just picked up a Lumia 650 for a daily driver. As a comm device and daily organizer they are quite nice. Not super speedy, but gets the job done and for 8MP non-PureView it still takes nice pics.
You might want to go that route yourself. Having used an 830 I know that camera is top shelf. You could still enjoy that tremendously and have a built for W10M device for daily carry and they do seem to be smoother at 10 then upgrades. Best of both worlds really...
I'm so committed to this course that I added a 1020 on 8.1 and ditched the 650 for an Idol 4S Windows as my daily. I think I'm on the right track.
YMMV
http://forums.windowscentral.com/gen...-eight3oh.html