How much of an advantage is this over a mini or studio with an external display?

There's no advantage whatsoever unless you like the look of a display with a huge "chin" and hate cables with a firey passion. Using list prices, the iMac costs $300 less than a studio display with the same screen. You get a whole computer for negative money. Shows you how much money Apple makes on storage and RAM upgrades! But of course it won't remain useful for as long. I know people who are still using the Cinema Displays from over 10 years ago.

> Using list prices, the iMac costs $300 less than a studio display with the same screen.

I think the old 27" iMac may have used the same screen as the current Studio Display, but the current iMac has a smaller and lower-resolution display.

Oh, you are right, apologies. You can get a pretty nice 27" 4K IPS monitor for less than $250, but not from Apple. Would probably depend on whether your eyes are good enough to tell the difference between 163 ppi and Apple's practically proprietary 218.