The poly concierge lounge is great...The lounge is in the Hawaii building, so if you want to be close to the lounge, request a concierge room in that building...the lounge is 2 floors...the lower floor has all the food out and table....the upper floor is smaller and is basically a quiet sitting area...there are huge windows that overlook Bay Lake and you can see Cindy's Castle out in the distance...at night during the fireworks, they dim the lights and play the same music from the MK as you enjoy the fireworks show...
I haven't heard too much about the CR concierge, but a friend from work stayed there last month in the tower and complained about the noise from Chef Mickeys...
From what I have read, the Poly concierge ranks among the best...although I have been hearing good things about the AKL...