Two questions:
1. What version of Lollipop are you on: 5.01, 5.0.2, or 5.1.1? The 5.1.1 could be the reason for your perceived improvement. Just sayin'...
2. If you're not up to 5.1.1 yet, have you run the StageFright Detector yet? I'd be curious if Samsung's patch worked for anyone on...