We spent 3 nights at the Carimar and 3 nights on St. Martin. If I had to do it again, I'd have spent 4-5 nights at the Carimar and 1-2 nights in St. Maarten. For a family vacation, the fact that you get two bed rooms, the living area, and the full kitchen is very convenient. Every morning we had breakfast on the patio and would then head to the beach, which for the most part we had to ourselves. The lack of air conditioning in the living area wasn't really missed and as others have said, it is now standard in the bedrooms and allows for a good night's sleep.
The staff was very friendly and helpful. At check-in I mentioned that we had reserved a car with Avis. They went ahead and called Avis and arranged for them to deliver (and later pick up) the car at the hotel, saving me both time and cab fare. Our maid taught us how to fry plantains and one day brought us a freshly picked papaya.
As others have said, the Meads Bay is superb. The hotel provides the lounge chairs and umbrellas, towels, and snorkel gear. Plus you're just a short walk to Blanchard's, the Straw Hat etc. With a car (highly recommended) your an easy drive from many more places.
In brief, the Carimar allows you to get away from it all, but not too far away.
Just a couple of other tidbits: We were advised to not drink the tap water, but to buy bottled water at the grocery store. (The hotel starts you off with a large free bottle in the fridge). When you visit the nearby grocery store to buy that water don't freak out over the prices as they are in EC$'s ($110 EC = $41 USD = breakfast for the four of us for three days). I didn't think about getting a GPS with the car and for the most part didn't need one, but we did get hopelessly lost trying to find Limestone Bay. Eat at at least once at B&D's barbeque. Get your morning coffee and fresh pastries at Geraud's (10 minute drive).