Reviews of the "Google Play" (i.e vanilla Android) editions of the Samsung S4 and HTC One complained about a similar drop in camera quality. Apparently, Google's default camera software just isn't very good.
Current Phone: LG Optimus G Pro (CyanogenMod 11 -- Android 4.4.4 KitKat)
Motorola Atrix (2011-2013)
Pantech Matrix Pro (2009-2011)
Motorola RAZR (2006-2009)
Nokia NKW-1X 1260 (2004-2006)