We absolutely loved staying at the Bat Cave. The grounds were amazing, and while we didn't book the place for the badminton, we did play for hours each day.
Location was perfect for getting to and from the ferry. A bit far if you are trying to be in Victoria for most of the day, but we loved the proximity to the parks and Sidney. We also loved the trails that were right in the backyard!
Would definitely stay again, but maybe not with 4 people.