Parrot's Nest is a terrific spot. Theo and Marcus are generous hosts and will help you with anything you might need. They have a ton of great suggestions on things to do around San Ignacio, but also in other areas of Belize. They helped us find the best tour group and guide for our caving trip to ATM, which was our favorite part of the whole trip. The area they have their cabins in is beautiful and feels like you're secluded in the jungle even though the town is just a few minutes drive down the road. They do have some noisy neighbors that play loud music across the river at night, which disturbed the peaceful vibe Parrot Nest has going on, but they did seem to stop at a certain point in the night before it got terribly late. It was absolutely gorgeous waking up to the sound of the river and the birds with the sun coming through the trees as well.
This is a perfect place to stay if you're traveling through or looking to get away for a while. It's a great location to be for most, if not all of the caves (our guide, through River Rat, even came and picked us up), and it's not a long drive back to the coast if you wanted to head there at some point as well (maybe 2-2.5 hours). It's worth coming here, and I would recommend it to anyone thinking about it!