I don't really want to play with a coupler...since I don't care what is in-between the cars. Now, would I put a Seargent on the point and rear of a train??? You bet! They look nice, and I don't have to fool (IMO) around with too much manual operation.
However, if they are only good for Shelf Models, why buy a more expensive coupler for just display? If you were going to do that, you need to get some of those look-a-like dummy couplers (like I did) for the shelf models.
Now, personally, about 98% of my rolling equipment has Kadees. No horn-hooks, but the rest (well, really not
that many) have Seargents. Now, yes. If one was going to have a operating session, or something similar, go for it. They give it a realistic appearance and feel. However, in everyday train running (What I do) I just want the train to run, and keep running, without my assistance for the couplers. They are good for a person who really wants the true feel of running a railroad.
Will I buy more Seargents? I don't know yet....
Phil