Actually the rooms at both PO resorts and CSR are exactly the same size. Among the moderates, CBR was the first moderate built and has the largest rooms at 340 sq feet. CSR, POFQ, and PORS rooms all have 314 sq ft. CBR is also the only moderate that does not yet have queen size beds (only full), so those smaller beds make the rooms seem even larger.
Oops, I just saw your second post. When we took our then 3 y/o GS down there in Feb 2012, we chose POFQ specifically because of the smaller pool slide. He loved that slide and pool. Free life vests are available in the gift shop. However, CSR has by far the better kids playground of all the moderates. We still chose POFQ though, because the resort is so small and compact, no room is very far from anything else, so we knew it would be easier with his little legs, plus we knew he'd like the boat to DTD. The clown masks in the food court did make him a little nervous the first day or two though. However, he loved the alligators and sea serpent slide at the pool. Go figure!
For kids that age all four moderates would have their advantages:
CSR has the most comfortable beds, by far the best kids playground, and has the white sand beaches over in the Cabana section for the kids to play on. I also think that consistently CSR has the best bus service of any WDW resort
POFQ is so small that nothing is very far from anything else, which is great when you are coming in tired at night or need to make a run over to the food court. It shares buses with PORS, but the buses to the parks pick up at POFQ first, so going to the park in the mornings, you should get a seat. We also love the boat to DTD and smaller sea serpent slide at the pool.
PORS has the best food court and boats going to DTD pick up first at PORS. Again we love the boats to DTD
CBR has the largest rooms of all the moderates and also have pretty white sand beaches for the kids to play on. They also have a wonderful kids water play area that has no comparison at the other resorts, and since big kids are not allowed in there, it makes it very nice for little ones. CBR would definitely have the best water experience for kids your age.