I made the opposite move last month. Ditched my iphone 6+ and went with a Samsung Galaxy S9+.
Apple soured me with their bullshit around throttling the CPU to make the battery last the same. No wonder my phone was performing like shit.
But here's the bad news, this new phone I got is still not so hot. I still run out of battery despite working from home and only using the phone for google maps and calendar/slack when I'm out of office. I don't game on it or anything.
For my next phone I want to find a much more inexpensive phone, swappable battery, with a long-ass battery time. I would go with a Nokia but I don't know if their classic phone supports google maps.