Depending on how young your kids are you may want a bottom floor room.
This way if they nap (or one of them naps), you can lock the front door to your room & sit outside on the lanai.
We did this on our last trip when our daughter was 15 months old. When we went back to our room for our mid-day break we put her in the crib & we went to sit outside to read, talk, etc...
We were also able to take turns doing laundry with one of us sitting out there (the door was cracked open to listen for her) & getting drinks/snacks.
We plan on doing the same this summer since my son will be just under 2 & still need to nap so one of us can stay on the lanai while the other takes my soon to be 4 yo daughter to the pool during our breaks.
Even though it is nice to be by the pools & GCH, you might want to think really hard where you want to stay:
If you stay too close to where the luau (can't spell that word) is, it may get noisy at show time (so I have heard as I have never stayed on that side of the Poly).
The pools can get noisy too. I have stayed in longhouses that are by the pools & have never had a problem but I have read about the noise from other sites in the past.
I prefer the 3 longhouses closest to the TTC (off hand I can't remember their names) just being that you are pretty much in between both monorail stops (the Poly's & the TTC's). Yes it is a little walk to the TTC & main pool but the walk isn't that bad.
And don't forget if it rains to know your way back to your longhouse by cutting through the other longhouses. My husband thought I was nuts one year (this was pre-being married) when I ran him through about 4 longhouses just to stay fairly dry. He has since learned how to go.
Kerri