Because of the 3 younger children and the fact that you will probably spend most of your time at MK, I would stick to CR or Poly. Being on the monorail is priceless. From there it's a matter of personal preference, as to what style suits you better. Poly is very family-friendly and has a nice laid-back atmosphere, but kids do love the monorail going right through their hotel! In spite of the many negative posts about the Poly, we have always gotten excellent service there. And, IMHO, you can't beat the magic of watching Wishes/EWP in your jammies from your room or the lounge, then going to sleep with the castle changing colors right outside your window.