So i've posted here before about how i preferred Sense 6, ONLY because of the HTC Camera App. Since recently, I switched to CM12, and I have to say, the ROM is REALLY smooth and fast. the camera on there is snappy, but the quality is still lacking. I then installed the HTC Camera from the Play Store, and it works! So now I can say I like both the AOSP or GPe since I can install the HTC Camera.
I just think HTC's camera app was optimized for the 4 Ultra Pixel Duo Camera on board of the M8.
I think this is where HTC has earned a future customer, minus the M9 cause of the minor aesthetic update. M10 will probably be my next phone, even with just a minor update to the look of the phone.