This is a wonderful shot that you took of the stairs, but one question I have is how in the world did you get this picture without any tourists in the photo? I have rarely seen this stairwell empty. Thanks for sharing.
Glad you like the stairwell photo. I was there around the time they were closing, and even then I had to wait a couple minutes to get the shot.
Just for grins, I decided to re-process the photo using Lightroom 4 and here is the before and after:
With Aperture 3 (prior to v3.3) using highlight recovery and Neat Image:
With Lightroom 4 using highlight recovery and noise reduction - note the retained detail near the bottom of the stairs. I checked and Aperture 3.3.2's updated highlight recovery performs similarly in retaining detail.