Did my own comparison yesterday by playing an mp3 on my PC and seeing how well the mercury picked it up audio wise, I placed the phone on my desk and recorded video using the stock huawei app vs. lgcamera, I then extracted the audio into .mp3 format from each video, The difference is pretty insane..
It's amazing to me Huawei chose to use such a poor quality setting even when recording in HD 720p, anyhow lgcamera works for now and I haven't noticed any negatives vs. stock app other than it taking a little longer to initialize.
MP3 format files:
Stock Huawei camera app: Link.
Lgcamera app with AMR_WB encoder selected: Link.