I don't doubt that it has improved internals but at what cost? I understand Sony and Japanese engineering philosophy strives for kaizen but after 6 years, at the same price (not counting inflation), I don't believe we got our time and money's worthIf you are serious about power you are going for the DMP-Z1. Otherwise this is a huge improvement in basically everything. The only drawback are for folks who want the Walkman OS rather than android.
-More battery
-Better Display
-USB-C
-Android 11
-Improved internals, shielding, and power delivery
Edit: Not saying that its a bad product but rather the iteration is feels like a yearly iphone kind of upgrade rather than a 6 year update