I didn't go in October, but we did go in September. It was lovely, so sunny and hot but was out of season, so while there were still people there, it wasn't absolutely heaving. It was perfect.
And, whatever you do, please don't let anyone tell you "oh that's hurricane season", yes, they are right, but because of where Antigua is, even the locals will tell you, hurricanes very rarely hit the island.
xx