We stayed at matachica for 1 week in one of the seaside casitas. You are about 30min from both san pedro and secret beach, so i recommend that you rent a golf cart for your entire stay.
Breakfast on-site is included and was excellent, though if you get sick of your two free options you can order additional items at a cost. There are two bars, one at the restaurant and one outside under a tree, by the pool. The outside bar closes at 5p which is a bit too early IMO.
You can get kayaks and paddle out to the reef (took about 10min) then attach the kayak to a bouy and go snorkeling. Just snorkeling off the resort we saw an eagle ray, two dolphins, angel fish, octopus, eels, etc. We also did two scuba trips with White Sands dive shop and had a blast as well, plus they pick you up at the matachica pier!
The rooms are great but dont have mini-fridges, we went and bought a cooler and some ice from the store nearby (15-20min drive) bc drinks are pricey at matachica!
We enjoyed visiting secret beach, specifically: blue bayou, swing bar, and sunset palace. Prices are more reasonable out there too.
We had excellent dinners at mambo (at matachica), portofino (fancy place just north of matachica), and carambas (amazing seafood in san pedro—our favorite place overall).
We had excellent food/snacks/lunches at the matachica bistro (served out on the pier), Capricorn, crocs, rum dog, and pur.
The best thing about matachica is the staff and the view, the worst thing is the sea grass. The sea grass coats the eastern shore of the whole island and smells like rotten fish if you get closer than about 10ft, so for our beach time we went to secret beach. If you want to relax at matachica for the day, you can sit out on the pier so the sea grass is behind you or you can hang at the pool. Im not sure when sea grass is there and when it isnt.