It was great to hear about these secrets. We've just booked the Millenium for the Nov 05 Transatlantic and booked cabin 6033. By really scrutinizing the pictures, it looked to me like the balconies were larger in that area. Thank you for confirming that!
We took the Sept 04 Transatlanatic and made a last minute change to cabin 6135; it became available and I grabbed it. It was great. Although now it is a Concierage Class, and rightly so, due to the extra balcony space. Not only do you get a bigger balcony, you have a clear view beneath you. Most of the other, center balconies have a view of the lifeboats!