I'll echo the sentiments above. Hawaii is better for golf, if that is important.
I was at all three resorts you are talking about this year. I loved all three locations. I own on Maui and WSJ-Bay Vista, exchanged into Princeville.
It will be very difficult for a third party to tell you which is best. They are all great locations, and which one to go to is a very much dependent on personal preference. I would probably try to go to all of them over time, and take whichever one is easiest to reserve first.
The facilities at WSJ are very nice. I ended up purchasing a Bay Vista unit because I liked them better than the ones on the hill that are older. However, those units have their own advantages and are appealing to many. The Bay Vista, and now also Coral Vista are new, and you should not have any qualms about staying there. The only concern for me would be that October is still well within hurricane season. Also, many establishments close mid August for the season, and I'm not sure if they would be open again in mid-October. Perhaps others can comment.
I like Kauai for hiking and outdoor activities. The resort in Princeville is nice, but doesn't have a beach. You really need to drive, take a shuttle or walk a while to get to the ocean. The golf course looks nice, though.
Maui is my favorite, with a good mix of civilization and tropical paradise, but the choice of favorite Hawaiian island is also a very personal matter. They are all beautiful and different from each other, and each appeals to different people. I try to go to all of them as often as I can, usually going to Maui and one of the other islands every summer.
I will tell you that for us, going to the resorts is MUCH better than staying at a hotel. I travel a lot and stay at nice hotels, but when vacationing, I really prefer a place that has a kitchen and a washer and dryer. I was just in Madrid, Spain, and canceled a points stay at the Westin Palace in favor of a paid stay in an apartment that offered more room, and said kitchen and laundry facility. It was our third week in Europe, and we wanted a change from staying in hotels the prior two weeks. I rely on VRBO.com for stays at places where Starwood doesn't have a timeshare.