The mammoth ships that carry thousands are, well, too big.
Small ships can manoeuvre better.
They bring you closer to the action around you, in the water and on land. Good food and accommodations count for a lot. Port formalities usually move faster on a small ship. With only 100 or so passengers to move, not 3,000, the process is smoother. Small ships tend to be more casual than larger vessels, although all cruise ships, in all sizes and shapes today, range from casual to formal, simple to ultra-deluxe.