The pools may not be EMPTY but it is definitely not a prime time for swimming no matter what seating you have.
The pools were definitely not completely empty, but for us, they were very uncrowded, i.e. my kids could freely swim around. The Aquaduck was literally empty, and we could ride, get off, and get right back on. It was nice. We weren't able to take advantage of the "non-peak" time when we had main seating, so having second seating made all the difference for us in that regard.