As a Nikon shooter and Aperture user one of the things that has always been a hang up for me has been the significant difference in color and tone curve defaults that Aperture uses as defaults when processing Nikon RAW files. In a lot of cases I like the look of JPEGs produced by Nikon cameras and wanted a quick easy way to reproduce the look of various Nikon Picture Control settings on RAW files processed using Aperture.
Historically I have set up various presets for the specific camera that I used at any given time. As newer cameras came out I would make new presets as I have found not only the camera but also Aperture changing through out the years to produce different results. When the Nikon D7000 was released I bought one and again setup Aperture 3 presets to mimic the color and tone of Nikon Picture Controls. This time I shot and evaluated thousands of images to test and fine tune those presets in an effort to reproduce the Nikon in camera color and tone results precisely so that I would feel comfortable unleashing them for other photographer's use.
I found that depending on ligting conditions, various color temperatures of the scene being shot, and camera WB settings that it was ipossible to reproduce Nikon Picture Control results as measured scientifically for numerous reasons having to do with the way WB and color are handled at the RAW processing stage within Aperture. What I did instead was then target a reasonable compromise again testing the presets with 1000's of images and in some cases sacrificed exact measured values in one case to cover different shooting conditions in a better visual way that was as close as possible to the Nikon Picture Control results qualitatively.
For more than a year I released the resulting presets in a limited way hoping to get as much feedback as possible in order to improve them to cover what Nikon shooters would consider as good as it gets. What feedback I have received has been positive and in some cases surprising. Surprising in that many Nikon shooters that were not using the D7000 have found the presets to work extremely well on just about any newer Nikon DSLR. Specifically the D700, D5100, D3100, D3200, and even the D800 according to people that have tried them with those cameras.
While I still do not consider these perfect from a scientific point of view - as they cannot be without adjustments based on shooting conditions - I now feel as comfortable as I can making them generally available and also recommend them for a quick way to simulate Nikon Picture controls over a wider range of Nikon DSLR's than just the D7000. Please let me know what kind of results you experience as well as any suggestions to improve them.