Oneta is definitely not your standard resort; there’s no pool, no buffet, no TVs and no day spa (although you can get a massage). If that’s what you’re after, this may not be the best place.
What Oneta does have is beautiful coral reefs for snorkeling and diving, fantastic food (you don’t choose the dishes, but they are very flexible to your tastes and dietary requirements as long as you let them know), some massive GTs for the fisherfolk and some of the best customer service you will ever find. Richard, the resort manager, works incredibly hard to keep all the guests happy; dive team and all the other staff are incredibly polite and helpful. It’s a small resort (6 bures, I think) and they really do look after you.
There’s very few extra charges (you only pay for alcohol and activities that use petrol - no charge for getting laundry done etc) and the prices for drinks and activities are very reasonable for what you get. Only warning is for the fisherman on a budget - if it’s rough then the smaller boat can’t go, so set your budget a bit higher or bring a friend to split costs. I would recommend bringing your own popping and stickbaiting outfits if you can (and if they’ll fit on the tiny plane - check the limits!), the gear is serviceable but not spectacular.
I don’t know if Oneta is for everyone (I suspect my mother would hate the lack of meal choice, TV) but if you love to do stuff with only one or two rest days then I cannot recommend it highly enough.