Lovely when the water cooperates and the yahoos stay home
We do the boat-in camping 2-3 times a season for the past 7 years or so. The coves are great but it's a bit of a gamble as sound travels so well and yahoos are prevalent. If you get one party boat who plays music medium-loud until 1am you are going to be grumpy and your kids will be super fun the following day.
The water also will go from so far above the trees that there is no shade to so far below that you're hoofing your gear 100 yards from the boat in the mud up to your campsite. Just be flexible and you'll have fun.
Kids have a blast swimming, kayaking and just goofing off. Adults chill and drink and fish. Most spots do not have bathrooms (bring a shovel, bag/remove your solid waste and keep it clean) or any other facilities except a fire ring.