The AIs in Jamaica seem to over-hype the "danger of leaving the resort", and guard em like prisons. why? cause they want you and your money to stay at the AI. Plenty of add on charges to be had by most AIs from tours to beach umbrellas. One of my friends' will never get outside a gated AI in Jamaica because his wife has been brainwahsed into thinking its a war zone.
As for Ocho v Negril - forget about Ocho. Total tourist trap.