First off, the resort was gorgeous and the staff were friendly.
The policies on the other had were not. All prices at Matachica are in USD and then add GST and "service fees", which adds ~27% to everything. Most of the island lists prices in Belizian dollars which are half a US dollar, and most other locations include GST/etc in the listed price.
All the activities from the resort are more expensive than booking yourself by as much as 50%, for no really added value.
The rooms do not get "dark", since the only curtain that faces where the sun rises is translucent. Expect to wake up at dawn when the sun assaults your eyes. They also are perpetually sandy, but that's due to proximity to the beach.
Do not let the "free breakfast" fool you, like it fooled us and others, it is only one item on the list, and it is not called out on the menu. If you deviate from that, expect to spend closer to us$50 for breakfast for 2 ($12 each breakfast, $6 per drink, plus GST, plus service, etc).
The road is more potholes than road, and with the frequent rain, full of water. Riding the bikes provided by the hotel is an exciting challenge of how wet and dirty can you get. Riding in golf carts (rent from in town for half price, compared to the resort) is also a test of fortitude and spinal compression. If you venture off the main road to secret beach, know that road is somehow worse.