Keep in mind I have no idea what you as an individual like / don't like or expect in a cruise or excursion----having said that, we have been to Labadee 4 times. The last time was a couple months ago in Sept. We are not the type who can lay out on the beach all day and as we had been there 3 times previously, we were wanting something different to do and took the tour you mentioned.
It's about a 2 hour tour in a fairly good sized boat, covered so there's shade but you could sit up top or below out of the sun, as you desired. The boat doesn't go very fast so there's no motion to speak of, in case you have a problem with that. It basically goes a few miles around the coastal area where there are villages, houses, etc. and some very beautiful scenery. There were people out in small boats with home made sails , fish traps, etc and the water was very beautiful. If you looking for a pretty relaxing tour on the water, not too far from the land and seeing some beautiful scenery, it's worth it. You can see the Citadel, which is now in ruins on a mountain top but it's so far away it's just a speck so don't get your hopes up on that. It you're into wild adventure and excitement, I wouldn't recommend the tour.
We enjoyed it , as it was something different from what we had done the first three times we were there, which was basically nothing.
After we returned to the main area, we had lunch, shopped a bit and then rode the Dragon's Tail coaster. I would recommend that too. It only last a few minutes--2 can ride in one car and to me it was a blast.
Again, It's hard to recommend a tour to someone that you have no idea of their likes or dislikes, but if you're wanting to see some beautiful scenery and don't mind spending a couple hours out on the water it's a good tour.Think about the Dragons Tail afterwards too-- I loved that.
Go to RCCL website and under excursions you can pull up a short video of the Dragon's Tail coaster ride. Or if you really want to get on the wild side, do the over the water zip line .
Hope this gives you at least a little useful info . and enjoy your trip.