rob and i stayed at the beach club during our first two trips to wdw. we've been to beaches for lunch, dinner, and desert. we didn't go often but we liked it. it's hard to say when's the best time.
i do suggest to stay clear there when it rains. everyone from the pool immediately goes to beaches for a snack while they wait for the rain to clear. it's almost impossible to get seated. we never tried it but we knew the headache we would've gotten.