We took a few ships excursions on our small ship cruise this past summer, we were generally a group of 10-20, so very manageable and quite enjoyable. We did the majority of the ports on our own, either just walking to what we wanted to see, or taking public transportation.
August 2002--Disney Magic Eastern Caribbean
October 2005--RCCL Mariner Western Caribbean
October 2011--Disney Dream Bahamas
June 2012--Windstar Wind Surf Back-To-Back, Rome to Venice to Athens
April 2014--Paul Gauguin to French Polynesia
Three weeks in Europe (two on a ship) with a 20" roll aboard and a tote bag--packing list here.
My all in a 20" wheeled bag for a warm weather cruise packing list here
20" rolling bag packing list for two weeks in a cool/cold climate here.