Let me begin by saying that we are not fans of large ships, as the crowds can be daunting. We have done 13 cruises on ships from 16 to 3000 passengers, chosen mainly by itinerary and scheduling. Most of our cruises have been on the Star Clippers sailing ships (which we love), but we have been on a Costa and a Carnival, as well as a Queen Mary 2 transatlantic crossing.
We opted for a large ship this time to go 'round the Horn, a long-time bucket-list item, considering the seas involved in this area. We're glad we did, and the Star Princes handled the 20-foot seas and the force 10 winds pretty well. You still knew you were on a ship, however. My guess is that the QM2 would have been smoother.