We stayed at T.R.E.E.S. for 3 nights and loved being far removed from a city, with the beautiful Maya Mountains out our front door. We traveled around Belize by bus, so this place was very easy for us to get to. It was a great place to just unwind and hang out in the swimming hole, and to hang in a hammock reading. We ate dinner there every night, which was delicious, however didn't seem very Belizean to us. We were there over a long weekend, so all of the local staff were off and it was quite obvious they were understaffed. Also, the waterfall hike in the description actually costs something like $30 or $40 US per person to get to since it's not on their property, so don't count on having that activity to do unless you want to spend a lot.
The cabin itself was amazing, a really good size, and clean. And you just can't compete with the view from the cabins. If you're looking for a place out of the city to unwind, see some wildlife, and to meet some awesome people, especially if you're interested in biology, then this is the place for you!