Going back in the thread I see some prefer AAC over AptX. Will need to do more research. FWIW I have Developer options unlocked on my S8 so I can force either one and instantly switch. Not noticing much difference.
Apt X was over hyped for sure, unfortunately it has muddied the waters.
Apt X isn't a great codec for quality, AAC beats it easily in terms of quality, but AAC is more expensive to decode, especially in low latency applications, not for Apple though, they were obviously screwed by Qualcomm, not getting AptX HD, they'll probably pay for that later but there are different opinions about what will happen next. I don't have a crystal ball for Apple, I don't get why they aren't even playing this game yet, possibly still pissed about hardware contracts they keep failing to hit (some might say they did it deliberately, but I think it came down to price). AAC is an excellent codec for lossy compression, Apple might just increase the bandwidth and continue using AAC, only increasing the specs when they want to achieve CD quality over Bluetooth.
AptX HD isn't a great codec, but the standard is a higher bit-rate than AAC can do over Bluetooth, so because of the higher bit-rate, AptX HD is better than AAC over Bluetooth.
On this ES100, Apt HD > AAC > Apt X > SBC
I'm just talking numbers here, which are objective - once the signal gets to the DAC, then it comes down analog and the ES100 is IMO, much better than most of what's out there, not as good as the higher end audio phones like the LG V20, V30, G6 etc... using their native 3.5 mm jack.
Some people's ears prefer hearing compression artifacts over signal purity, so it's also a matter of taste.
