Oh yes, the pools at both hotels will be crowded during the hot summer months. But from our experience that's pretty common at all large hotels. A good tip is to go swimming when most people are packing the park. That's usually when we go back for our breaks anyway. Go for a swim, take a nap, and then hit the parks again when other people are out having dinner ect..
The pool last year at DLH was very clean, hopefully when we go that won't be an issue. I remember last year I lost my wedding ring in the water! With all these people swimming around making the water move. Oh my gosh I was so scared it was gone for good! Thankfully the water was clear enough to see it shimmering and my DH dove down for it. Next time I'm leaving my rings in the hotel room safe! LOL