Well, I can only give you my daughters opinion of the excursions. She is soon to be 17 and has been on 4
DCL cruises. I will let her tell you her opinions herself:
I went on The Teen Junkanoo and I didn't have alot of fun. Basically what you do is you transfer from the ship to a small boat which plays loud (mainly rap) music. And all you do is float around because there usually aren't many people on it (I've been on this twice). There wasn't alot of dancing, there was a little bit of conversation when you could find a place in the music that you could hear around. And while a trip around a nice harbour at night sounds all nice and romantic and whatnot, it really isn't great because you can't see much of anything past the railing on the boat.
I also went on the Wildside Adventure which was awesome. We went out for the day and did some snorkelling, cycling, kayaking, and we ended up swimming at the teen beach in the end. They supply you with a half decent lunch on the island and a little snack and drink inbetween the cycling and kayaking. It was really alot of fun. The counselors were great fun to hang around with as well as the people. It involves a little bit of physical activity but as long as you know how to ride a bike it's not bad at all. And you have to have a sense of humour because there tends to be alot of joking and whatnot going on. Also it's great to be open to trying new things if you haven't snorkeled or kayaked before.
These are my opinions and I know that there are probably alot of people who loved the Junkanoo and absolutely hated the Wildside Adventure...go with what you feel you'd like to try.

Robin, back again, I hope my daughters opinions will be of help to you.