Sunni and Bob are great hosts. Very friendly and very knowledgeable about Utila, especially under the water! The cottages are very nice for up to 4 people. Amenities cover swimming, snorkeling, kayaking or just chilling. You'll have to kayak (very easy and easy to learn, even for this 65 year-old) to the cays if you want to get very basic needs or basic restaurants. You hire a panga (as low as $10/person one way) if you want to go into Utila Town. The pangas rarely go after dark or in bad weather.
Scuba is the thing in Utila. Most of the dive shops are in Utila Town. I went to Captain Morgan's as advised by Sunni and it was an awesome experience.
Sunni's Cove is a "get away from it all" experience. I suspect that the power will go out from time to time because the WiFi was iffy during a storm. If you want five star accommodations, go to Hawaii, but if you want something more real to life, something you'll never forget nor regret, come here.
Downsides: coffee is mediocre at best.