I am not sure about adding people as we only have 3. We rented one for the 1st time last year and thought it was fantastic.
We went in June and it was crazy crowded, it was great to have a nice shady spot that was just ours. The attendant was fantastic, it was very nice to have her bring lunch. We asked to be by the surf pool, as we spent hours there, and had a great spot.
We enjoyed it last year and have booked one again this year.