We moved to Turtle Inn after staying one night in a different Placencia hotel that we didn't like. We loved Turtle Inn. The staff was very attentive and helpful, from the moment we walked in. The grounds are beautiful and serene, and the rooms are spectacular. We stayed in a two bedroom villa, with a wonderful outdoor courtyard with shower, and the architectural touches were very nice. This hotel is proudly backwards in some ways - no air conditioning (but lots of nice breeze through the rooms at night), and no blender drinks (but the shaken pina coladas and daiquiris were unusual and great). The pools are small but the water is clean and refreshing. We walked through the grounds of Chabil Mar, the other well-reviewed hotel in Placencia, and the grounds could not compare - Turtle Inn is several levels nicer.
The only thing to note is that I would not make Placencia a destination, other than a stop on the way back from a resort on the reef, which is what we did. The beach in Placencia is narrow and, when we were there, not clean or appealing. The town of Placencia is nice, and Tutti Frutti is a world class gelateria in town. But it is not worth more than a day or two.