Tested both the S6 and S6 Edge and indeed, there was quite a significant difference between the 2. The sound quality on the S6 was garbage while the S6 Edge was more clear and balance.
S6 sounded extremely harsh with my westone 3. Male vocals had that sizzling high sound you would here when someone speaks through a cheap microphone. Bass was muddy to my ears.
The S6 Edge on the other hand, could match my Xperia Z1, only on the bass department though as i found it more control and detailed. When it comes to the treble however, my Z1 is still undefeated. Mids/Vocals are equal here, both Z1 and S6 sounded as good here.
It's just a pity that the Z3+ is not of a big improvement over the Z3 and the camera on the Z3+ is the exact same sensor on my Z1 which has already been defeated by the S6 Edge's camera. I'm considering to jump ship over to Samsung as the S6 Edge wins my 2 years old phone in every other areas such as the camera. Looking forward to hear more impressions regarding the S6 and S6 Edge. . While the camera is one of my priority, music/sound quality is my highest as i do not want to carry an additional device around.