Nokia camera is the much more comprehensive package by far, but in-quick shoot situations I use the standard Camera app as Nokia camera takes a long time to launch.
Actually, after replying to this thread I've spent time comparing the two apps. For day to day use, things that I would photograph, still shots of family and scenery, both apps provide the same quality photo. With 8 1 the default camera has brough a new interface and more settings, it's faster to load and easier to use than Nokia camera. So for me, I'm gonna go for default Camera.
I've always gravitated towards the Microsoft camera app but I have hunch that some time in the future we may see all the Nokia and Microsoft apps merge into one.
I installed Nokia Camera beta and its cool that when reviewing the burst it shows it moving when reviewing photos. I prefer Nokia camera because if you burst shot on MS cam the res is lower than if you burst on Nokia cam and choose best shot. Little things like that make Nokias a better choice.