My wife is using stock ROM, when making calls using loudspeaker mode, from my S4, I heard a lot of background and sometimes sharp noise interference and the audio of her voice is softer than expected. Its just like no noise cancellation and her casing has all its noise cancellation hole exposed. A bit disappointed with loudspeaker (on her lap) noise quality.

Have to compared it with my outdated S4, her side hear my clearly without any background or sharp noise interference just like speaking beside the ears. I guess the valued price does has its cost cutting somewhere.