Ports & related excursions were by-in-large extremely poor. Don't go on this cruise if you are counting on wonderful shore experiences UNLESS you are prepared to go off on your own. A big mistake was taking the excursions.
We embarked from Buenos Aires; excellent nite at the Tango with outstanding dinner. Arranged by Regent so one A grade here, but extremely disorganized in getting folks on the right shuttle vans to the right venues. You'll need to be proactive to find your way. Next day boarding ship delayed by an explosion in the port which closed it down for 6 hrs. Sheraton Hotel was amazing in providing a wonderful buffet for about 500 people in less than 2 hrs.
Next port was Montevideo - great walking tour but one could see more on your own with a good map. Oh, Regent provides absolutely NO MAPS - very strange, so come prepared with maps of the various ports in hand. Will be extremely helpful for you. And Regent does not do destination lectures prior to coming into ports and little good or reliable information in their publications the day before. So do your homework before traveling.