We have stayed at both. Love them both. It is more of a walk (which seems much further at night) to HOJO, but the water park is a blast. My kids loved it (they were 10 and 7 at the time). Honestly it is aimed at smaller kids, in my opinion, but my kids still loved it. Check out the youtube video so you can see exactly what the waterpark area looks like so you are prepared.
Saying all that, we LOVE BWPPI. It is super close. They have a pool too, nothing fancy, but it is still a pool and I enjoy relaxing in the hot tub during our afternoon breaks while the kids swim. Another plus is the free breakfast, it is basic, but we love it and it saves us money and time each morning.
Good luck with your decision!