I honestly didn’t notice much of a performance difference between the mic on this model and the mic on the old one, but that’s just my experience. Sony’s hidden mics in the Gold/Platinum headsets have always been strictly adequate. If you check out some other mic tests of Sony’s gear on Youtube you might notice a pattern!
And I agree with you about 7.1 surround being a problematic scenario on PS4…so much so that I wrote about it quite a while ago. :) Sony wants you to stay entirely in their ecosystem with surround sound, and third party options are stuck using the optical output on the Pro/Original model, whereas Microsoft has opened things up completely with Windows Sonic and Dolby Atmos to whatever headphones you’d like.