Why are you having second thoughts? What are you looking for in a resort?
I stayed @ the Poly in May. I have 2 kids 9,8. We all had a great time. I love the size and feel of the resort. I enjoyed walking around. I really felt like I was back in Hawaii . The staff were very nice and helpfull. I did run into one lifegaurd that was not acting very "disney" but the others were more then great. We had a great time participating in the pool side games. We played touch football/tag with the kids and others came and joined in (some looked to be 3,4) everyone laughing and having a great time. The kids built sand castles. We ran in and out of the pool. I loved having the option of watching the fireworks from the pool or the beach. The view of the castle is awesome. In fact I got up early each morning to have my coffee out on the beach while looking @ the lake/MK castle. I'm not sure just why I found this view to be so beautiful. I'm not really into that kind of thing.
The Gf is also a beautiful resort. I love being able to look over and enjoy it's beauty but much prefered the feel of the tropics @ the Poly.
I think my brother took his little boy (4) to the child care area and played free viedo games a few times. We just had a fantastic time and loved the resort. So if you like the tropics and being close to MK using the monarail and having a great bus service all with in a short walk ( 5 mins or so) I think you will have a great time @ Poly.