The Beach Club is a great place to stay - super close to the water taxi and just a few minutes walk from almost anything on the island. Jessy is a bit difficult to reach, but once you're there the people at registration are on top of everything and can get or help you with anything you need!
The room was simple and just exactly what I needed for traveling solo. I loved the chairs out on the deck where I could sit outside, day or night, and see the water. I highly recommend renting a bike from Mario's to get around the island, head to Ice + Beans for coffee and sitting out on the sand in chairs or hammocks, and hit the yoga class at Namaste Cafe if it's in session!
The only downside is that it was a bit loud with other groups and families staying in the rooms adjacent and above, but hey, everyone is on vacation so it didn't bother me. Everyone was all smiles, Caye Caulker is paradise!