I thought the zip lining in Puerto Vallarta was a lot of fun. You get to do a mix of things with the ATV's, the zip lining was great, and the indoor skydiving was really fun to try. The snorkeling there was fun and the crew put on a good show on the way back too. I thought the hot air ballon over Teotihuacan was really nice. It was an amazing view and nice experience. I thought the whale sharks was cool experience, but sort of expensive for what it was. Coco Bongo in Cancun was a really cool place as well. The show they put on is great. I think the best included meal was in Belize, and I did appreciate that the breakfast there was at a local restaurant and you could order what you wanted instead of just the continental breakfast of a hotel.
One of my biggest disappointments on the trip was in regards to food. Other trips I have done with Contiki have done some kind of food tour or we at least went to multiple places to try new or different things. A lot of the restaurants we would go to felt more touristy, were expensive for where we were at, and lacked flavor. We didn't really get to try much of the local food, or much that I would say is unique. It honestly felt like we would go to locations where our trip manager knew the people there and might have just gotten a kickback for bringing people. One of the restaurants we went to, a few people complained they did not like the food, or that it was not very good and our trip manager was visibly angry with the people on the trip. When we said we wanted to try the food markets or more local food, our trip manager said to avoid anyone getting sick we would really be going to more approved restaurants. We stopped at a food market I think the last day when we were in Mexico City, but it was for about 20 minutes or 30 minutes, so by the time you looked around, it was pretty much time to leave. We did a walking tour in Mexico City, but it felt very quick, and more of a jump off the bus, walk over here and jump back on the bus just to say that we did it. It was called out that one of the biggest forms of transportation in Mexico city is the subway. I think it would have been interesting to have actually taken it somewhere to explore the city if it is the main form of transportation there.
I would say most of the hotels we stayed at were alright. There was one hotel we stayed at though with a water slide, but the water was pretty gross. There was a lot of chunky stuff floating in the pool, and a dead bird had been in there for quite a while. My only complaint with the hotel in Cancun was that the majority of the elevators did not work.  
It very much felt as though the trip manager payed much more attention and talked to the girls on the trip than the guys. More than once it seemed like he was flirting with or hitting on the girls on the trip. I feel like it also started off in a negative way when the trip manager says do not ask me to translate, do not ask me for recommendations or directions. That's what google is for. I heard from multiple people that our trip manager would talk negatively about people on the trip to other people on the trip.  
Other things that stood out were the walking tour we did in Guanajuato. We got to one point and then our trip manager just said hey FYI it is this much money now to take the lift up to where we are meeting. It wasn't a lot, but it's the fact there was no other option of if you want, you can walk there as well. It was just more of a surprise cost. I think the other thing that did bug some people on our trip was the pushing to tip every person we come across. I think multiple people had said just make the trip cost a little more and have the trip manager tip for everyone if that is the expectation.
In comparison, and after having done two other trips with Contiki, I would recommend the Southeast Asia trip. I just felt like that one was so well done, that I would recommend that one over the Central America trip.