We used to always book private tours where possible, however on our last cruise we had tons of OBC to spend so we booked ship tours, using the OBC and just paid the difference with the CC and I was so happy that we did.
My husband suffered a mild heart attack while docked in Edinburgh, not a killer but enough that we were off the ship for 9 days while he was in hospital. We were able to return to the ship after that time with the co-operation of the travel insurance company and ships medical team. Everyone thought it would be better to recuperate on board instead of a 24-hour flight home. The shore excursion team cancelled and refunded the tours for that time and worked with us to change other excursions that may have been too strenuous for my husband.
If we had booked independent tours, I would have had to cancel all these tours myself and probably received no refund. This would have been extra stress that I didn't. need at an already stressful time. I think we will just book ship tours now for the peace of mind