As I do not like Android OS-based DAPs, have no need for streaming, prefer longer battery life per charge and am not willing to do the shenanigans in order to debloat even SONY Android OS-based DAPs, I will definitely stick to all my DAPs with SONY OS till they are irreparable due to the lack of spare parts.
On top of that all of them are rocking, even the smallest little brother NW-A55. And there is still the possibility to install MrWalkman's FW that is said to improve the sound quality even more.
That's why I do not see any reason to upgrade my SONY DAP fleet.