Eastern Car on Magic vs Fantasy?

[JJsmama]

Hi, we are looking to cruise in mid- late April. There is an itinerary on both Fantasy and Magic. We will be just two adults. We have sailed on Magic and Wonder but not the 'new ones.' Are the bigger ships still extra crowded feeling? Which is better for adults only? Which is better island wise? We have been to St Maarten and i loved the beach there (opposite side of island from ships.) is CC lots more crowded on Fantasy days?

Thanks in advance.