IMHO, with the wealth of apps for shooting and editing there should be no reason not to make 13 MP work, even if it means a few tweaks every now and again.
I also think f/2.0 will let me in for better low light pics than I currently get with my 20 MP f/2.4 Lumia 1520. And way better quality when cropped in than my 8MP f/2.2 Lumia 640.
I've had the BLU Win HD and Win HD LTE and on the surface, the cameras are a shame, but with alternate capture apps like Camera360 Sight and ProShot I found them very usable... I'd like to see OIS, but I guess that is a no go. Doesn't mention EIS either. I'm still confident I can get some good shots with it.