I'm not sure that even the end gates at DTW or MSP Concourse A are quite as far as Delta's JFK T4 extension.

Remember Terminal A at DTW may be very long, but, unliike JFK T4, it is accessed in the middle of the structure.

The only time the walk at DTW has to be epic is if your connection is at the other end of your arriving flight, which--in my experience--is rare.

And if you do have to go from one end to the other, then you can just take the excellent express train.

Similarly, although MSP's Concourse A is indeed very long, there is also the Concourse A/B/C tramlink.

As was written in a post above on this thread, there is a shuttle bus from the outer gates at JFK T4 (B54), but it runs so infrequently that--unless you hit it as a bus is leaving--you might as well walk (if your primary consideration is time).

Here is a map of the current configuration of JFK T4:



You'll notice how much longer the DL concourse is that than the top concourse.

Before the extension, the B concourse ended at B31, which was already fairly long.

It is what it is, but the very long walk, combined with the fact that (for those traveling domestically with checked bags) domestic baggage claim is all the way on the north end of the main terminal building, makes this one of the longest walks in any airline experience.

As far as other airports around the world being similarly designed, yes there are others, although, in my experience, the worst is ARN, where the walk from one very linear terminal to another can literally extend for kilometers.