never been to CM, i know it is older than some places, and north of the town. when i stayed north, i stayed at journey's end, and the beaches are lovely, but didnt care for it much. next year i am honeymooning at xanadu, which is newer and south of town. folks tell me it's great.
i personally like the south end better, but everyone has their own opinion. either way, if you come with no expectations and an open mind, you will love belize!