Our vote is Kidani pool. There are showers, changing stalls and lockers etc, same as Jambo but the pool is by far our favorite and a very nice pool side food menu at Maji pool bar.
I used the showers at the Kidani pool & just so you know there wasn't any air conditioning where you get dress. I was swearing by the time I was done getting everyone changed. This was 2 yrs ago so hopefully they fixed this.