Re: Realism without differentiation...Better audio is probably irrelevant to most buyers.
I'm fairly deaf and what matters to me is not audio quality (though it helps distinguish consonants, there is that) but volume. The sealed phones all seem to have rather quiet rings, in fact I had to ditch my Sony because while on headphones it was adequate, I was missing calls even on maximum ring volume. I've noticed that Chinese phones tend to have much louder rings but are not watertight, and I draw a reasonably obvious conclusion.
Samsung Galaxy S8+ ring volume 71dB
Sony Xperia XZ Premium 71dB
Apple iPhone 7+ 72dB
Oneplus 5 77dB
Xiaomi Mi 6 84dB
If the tradeoff is between volume and water resistance, then mine is the one with the plastic bag in the pocket in case of heavy rain.