For people experiencing a little higher power drain with kp50 having exactly the same applications as in kp49, I noticed for example in my case that Advanced Power was draining the battery more than in kp49 (i.e. a lot of hildon-desktop-menu CPU), so after I uninstalled AP everything went back to normal. So this means some previous applications might not work as expected in both kp49 and now in kp50.

On the other hand, Advanced Power was needed because default battery status is reporting wrong percentage and signal low battery level earlier than bq27200 module. So I will manage for now without AP or default battery status icon and display the bq27200 data with QBW on desktop only.