I have all 3 phones; V20, V40, and the Note 8.
I got the V20 as a backup phone in 2018 because the price was so good and it has the SD card. It got Oreo and it's been a fantastic phone ever since the Oreo update. Love the removable battery, 2nd screen, Quad Dac and camera.
I had the S8+ but went to the V40 because of the Band 71 on T-Mobile (the S8+ did not have it). The reception is so much better for me at work. I work in a 2nd floor w/no windows lol. Camera is great, Quad Dac, super smooth UI.
I love the Notes so I picked up a used Note 8 for the heck of it at a really good price and love that. No Band 71 but it got Pie/One UI and Dolby was in that update. It's nice to have Dolby (not as good as Quad Dac but it's good enough for me w/some tinkering w/Samsung's audio profile settings)
I love all 3 phones and switch off for daily drivers.