Location, location, location!! In the middle of everything. Walk to more restaurants than you can sample in a week, more tour operators than use, gift & grocery stores, etc. Yes, it’s a busy place and noisy as some have noted, but that‘s all of Ambergris Caye except for the resorts out of town and a noisy, bouncy golf cart ride into town.
Comfy bed (best of all Airbnb places), nice, large, hot shower, useful kitchen, and (best of all) rooftop veranda for meals. Bathrobes were a nice touch. There are steep steps (by USA standards) to the top floor unit.