TL:DR: Loved the house, but would probably never stay at a NCIC property again.
Our party of seven (four adults, three kids) rented Manatee Manor for a week over new years. The house itself is very nice, unbeatably close to the beach, and very nicely laid out for groups (each bedroom has its own bathroom, for example). Unfortunately, the service from NCIC left a LOT to be desired, to the extent that it pretty much derailed the first three days of our week-long trip.
First of all, it took over two hours to get our luggage and bags after we arrived on their ferry, so we started our vacation with three little ones losing their minds because it was 9pm and they hadn't had any dinner--and we couldn't leave to get dinner at the restaurant because we had to wait around for the bags to arrive. When they finally came, all the breads were smashed and the frozen stuff had thawed. Awesome. 
The even bigger problem was the water in the house. Our first morning there, the showers didn't work. No water came out when we tried to turn them on, and the water from the sinks smelled like straight bleach. The one load of laundry we were able to run the first night came out literally bleached, just from the water. Called management the first morning and was told someone would come around to look at it. Waited around; no one came the entire day. Called both offices again in the evening and also emailed; got no response. By morning, there wasn't even water in the sinks and the toilets wouldn't flush either. (Seven unshowered people in a house with no flushing toilets: not exactly paradise.) Called both offices AGAIN, and also sent one of our party over to the office, and then waited around again all morning; finally a guy arrived around lunchtime. When he came, he said, "Nobody told me about it until this morning or I would have come over yesterday." (?!!) He got the water running again, but it was still so chlorinated that our teeth were stinging and another load of laundry got bleached, so we had to call AGAIN the next day and have someone come figure out the chlorination issue.
As yet, no one has made any offer to make up for the first half of our trip being riddled with problems. No partial reimbursement; not even a free drink at the bar. Problems happen, but when they do, I expect it to be made right. And no running water is a pretty big problem. There were smaller things too but, alas, I'm out of space to type.