We just got back from being on the Miracle. We had an extended balcony in the middle on the 8th floor. I can tell you most definitely, Dwayne is absolutely correct about the chair noise. Even where we were you could hear it constantly from early morning into late night hours. Although the extended balconies are very nice it was definitely not worth what we paid to hear the constant noise.
Other than the noise, it was a great cruise and we have already booked another.

We took advantage of the 100.00 OBC, and also received 2 vouchers for 200.00 ONC if we have friends that want to join us on the same cruise. Not sure if that is something new or not. We also bought another 100.00 certificate for a future cruise.
I also agree with Dwayne that the the Aft deck 4 suites shouldn't be a problem from what I had seen but I can tell you that when you look down on them from above you can see part of the balconies, but again this was on the miracle.