Sailbum pretty much summed it up. From my limited experience with Grenada (will have more insight into Grenadines in 6-7 weeks!) . I would add, I am not sure how prevalent power cats are in the windwards, a lot of them in the BVIs. Also wind gusts especially going around the north and south tips of the islands will be more variable, greater currents and swells. All in All a more challenging sailing grounds but much more fun!