I upgraded from the iPhone 6 Plus to the iPhone XS Max, on a complete whim. The biggest difference is of course, snappiness of applications. The OS, not so much, because I think Apple does a good job at maintaining iOS. But Spotify used to take 8 seconds to cold boot for me on my 6 Plus, and sub-second on the XS Max.

I would love to see hardware upgrades halt for five years while we all (collectively) get our software shit together and optimize everything for performance. That'll never happen, because I think it's in our human nature to Get Things Done in the short-term with compromises that affect the long-term.

Poor software performance is our digital world's global warming.

Worth remembering that CPU is throttled to battery health over time, so you’d want to compare your 6 as it was on day one. Not to say that your new phone isn’t faster, but your Spotify example is exactly my experience just getting a new battery for my iPhone 6 two months ago.

The reason I am happy with the 6s is that there's a big difference in speed from the 6 and earlier hardware. It's probably not quite as snappy as newer models, yes, but lag in moving around is something that I can't stand - and I find the 6s doesn't annoy me.