Can't go wrong with more oil capacity. The only downside I can see is the *gasp* factor if one decides to fill up with a premium-priced synthetic, or even a premium-priced dino when compared to the smaller ones the person is likely used to. The overall cost will be the same or likely even less especially in a heavily loaded engine in hot climates, as the oil will stay cooler and not break down as much that way.
Sump capacity, along with the near continuous running (lack of cold starts) is how large trucks can run such long OCI's and such long overall engine life, more often than not using plain old 15w40 conventional out of a bulk drum.