I've Z3 Compact and I'll be changing to SE. Not because of size, but because to my surprise Android is pretty spammy experience.
There is almost no control from google over what the Androids apps do, what permissions they request and for what reason, and how the data is used. All apps are able to reset your notification permissions on device every time they update. In effect, you can disable notification spam from apps, and then week later find they still spam your main screen, because each time they auto update, they can reset notification permissions, on their own back to all enabled. Even apps from reputable devs, like EA, have absolutely unacceptable amount of spam, with uncontrollable full screen adverts that cannot be closed and often launch subprocesses which persist on screen after main app is closed. It's also the only platform that allows full screen adverts from sat nav apps, while on move.
So, it will be the first phone in over a decade, which I am going to replace after less than two years, but my android phone just has to go...