We have stayed at both resorts and have enjoyed them both. As 2 adults w/o kids, I would have to say we would prefer the FQ because it is smaller and has a secluded spa. We will be staying at POR in 2 weeks because it had a discounted room available with a King bed and POFQ did not. As for finding things to do for 2 weeks with only 4 or 5 days in the parks, all I can say is good luck. The Moderate resorts at WDW are great, and we enjoy them immensely, but it might be hard to find something to do for 9 or 10 days unless the kids really enjoy the pool or are just into taking it easy. You might want to consider heading over to USF/IOA for a couple days. We didn't feel the same "magic" there as we do at WDW but they are both fun parks with plenty of things for your older kids (and the adults) to enjoy.
We were at POR in '99, when it was Dixie Landings, and I don't remember seeing a slide at the pool, although there may be one. The pool at the FQ has a nice slide for kids that looks like a giant sea serpent.
Enjoy your trip and don't miss Bob "The Piano Man" Jackson perform in the lounge at POR. He's a riot!