Last March and April we were on HAL’s Mediterranean grand voyage and use HAL’s shore excursions. Here’s my $0.02:
If you book a tour in Turkey that includes a ”carpet demonstration”, watch out. You will be descended upon by a bunch of Turkish carpet salesmen. (If these guys were in the USA, they would probably be selling used cars.) On our tour in Kusadasi we had the option of skipping this step because we were within walking distance of the ship. If you can avoid it, do so.
If your tour of Rome is only one day, make note of where you will stop. We only had two stops: St. Peters (worth it), and the Trevi fountain (a waste of time). Everything else was “drive by” sightseeing.