Good question.
I moved from a 5s to an 8+. The size of the phone is something I’m already used to after a week of use. I do miss the pocketability of the smaller phone though, and how quickly it could be picked up and used with one hand.
However, the improvements to my phone experience that the large high quality screen has allowed makes it worth it. Being able to use my phone for extended periods for work, photography and browsing is something I missed with the 5s.
There was a period when I was using a nexus 6P during my 5s run. Comparing that large phone’s dimensions with this one, I have to say the 8+ just feels better. I can even use with one hand for longer than the 6p ever allowed. Don’t actually know the difference in dimensions between the two, but the 8+ is preferable in everyway to me.
Finally, off topic somewhat; I’ve long been looking at getting an iPad after only owning the first generation all those years back. Initially after unboxing and using the 8+, I strangely started to think perhaps it’s not worth getting an iPad too, given the large screen of the 8+. But over the week the screen seems normal and not giant anymore and I again see how hugely different the use of a 10.5 or 12.9 screen would fit into my life compared with the large phone.