Apple's design really is something else.

Phone performance has reached its limit now, so there isn't much difference regardless of what you buy, but the gap in design is still massive.
With the Apple logo + iOS UI added, the Duo looks so beautiful.
If it weren't for memory chipflation, they probably would have posted record-breaking results.
I expect replacement demand from existing iPhone users for the Duo to last at least 5 to 6 years.