I'd highly suggest a private driver/guide for ports that are once in a lifetime type places. We would never take a group tour to those type of places, that is far from our idea of luxury. With a private driver/guide, you don't have the same time restrictions at a stop, as you would a group tour and get a more personal experience. Our TA has always booked the private tours for us, and if there was an issue with a tour, she has stood behind the booking and gotten us money back or a credit towards a future tour. Regent is our current favorite cruise line, but the included excursions have little value to us, unless it's the Caribbean or other places we've been to previously.