BeadBabe, I agree with CF, especially for those with no experience in the ports. I agree with you, that if you do your research, and you know the island(s) a tour on your own is sometimes a good deal. I've heard too many people disappointed with their "value" excursions and no recourse was available to them. A particular one was in St. Lucia where a group of them had to walk back from the trail they were on. They had rented horses and the "guide" decided they were rude, so he took the horses from them and left them in the middle of the trail. Luckily, they had done this in the morning, so they made it back to the ship. They were in a group of 12, so at least they had each other. I don't remember if they had cell phones or not, but some operators are shady. If there are firms that have good reputations, you might get a good excursion.
I guess I've been lucky, the excursions I've booked through the ships I've been on have been great. I've had some that were better than others. I've also done many on my own, but I have known the island and known where I wanted to go.
Is this your first time on the Epic? I just wanted to let you know that she's a fantastic ship. We sailed her last year and I have to say it was one of my top cruises. The entertainment was fabulous, the food was very good, the crew were great, and the ship is absolutely gorgeous. You need to try all the water slides, they were a ball! She's a strange looking ship from the outside, but inside she was amazing.