Not trying to scare anyone, but here is a look at the POR pool during a Spring Break week (leading up to Easter)...
The park crowd levels were a 9 or 10 most days we were there. So, if you are there at a peak time, this is what your pool will look like. It was a little tricky finding seats each day, but we always found some. People seemed to leave chairs without removing their towels.
The pool activities were great for the kids mid-day. It is a little loud, but my kids were always playing bingo, limbo, trivia, etc. According to them, it was one of the highlights of their vacation. The main pool has activities from noon to 5PM. It wasn't posted, but the lifeguard said the slide closed at 9PM.
One final note...it was 90 degrees everyday! So, lots of people looking to cool off.