Disclaimer -- I spent a week in Falmouth a few years ago doing mission work. I got to know and like many of the people.
Falmouth is one of the few actual towns that you can visit from a cruise ship. Most ports are built for cruise ship shoppers, and are not visited by the locals. Falmouth has its share of that, and it is the gated area right beside the docks. The shopping district outside the gates has no businesses listed on the port shopping guide.
The town might be the most interesting stop of any cruise. Not what you've heard? RCI tries to keep its customers in their dockside area. Monopolies are good for only one thing - high prices. If you are shopping, you'll find that the merchants outside the port area are pretty similar to the ones in Cozumel.
If not shopping, consider a walking tour. Get a map. Brave the merchants and the taxi drivers. Note - avoiding eye contact doesn't help, it makes the merchants more aggressive; just smile and glance over at what they are selling. Go to the part of town where the locals live. You may not be able to escape the guys who want to be your tour guide. What the heck, let one of them walk with you and keep you out of the more dangerous parts of town.
RCI has done a wonderful thing for Falmouth. The town is much cleaner than last time I was there. There are no longer burning mounds of trash in the middle of the streets. The merchants of Falmouth are learning to be more hospitable to cruise ship passengers.