Audio quality improvement between A50 models

Hello, I'm currently planning in upgrading my A50's from Gen4 to Gen5.

The reason I haven't done it, is because I have doubts regarding the audio quality in each model.

I play on XSX and the audio trough USB is mid, but if I plug the Optical Audio to the TV (because the XSX has no Optical port) i get the best quality.

So my question is, what would be the difference in audio quality between A50x, A50 (gen5) and A50 (gen4) ?

Would it be something like:

A50x > Gen5 > Gen4 (Optical) > Gen4 (USB)

Or

A50x > Gen5 > Gen4 (Optical) = Gen4 (USB)

Or

A50x > Gen4 (Optical) > Gen5 > Gen4 (USB)