I use Aperture 3.3, Capture NX2 v2.3 and Photoshop CS3. All my image files are organized in Aperture. I don't use iPhoto. From Aperture you can export an original image file (by a right click and select to send it to an image editor other than Aperture) directly out of Aperture to whatever external application image editor you want. You select it by choosing the application of your choice in Aperture Preferences and what kind of file you want to export by default. However, on my MacBook Pro (OSX 10.7.4) Aperture will only export the file as a TIF (8 or 16 bit) or a PSD (8 or 16 bit file) DIRECTLY to an external image editor like CS3. If I want to export to Capture NX2, I first need to export the original file (JPG, TIF or NEF (i.e., NIkon RAW)) to my desktop or some other folder and then open NX2 and bring in the image file for editing. It's not really a hassle to do this. Moreover, Capture NX2 handles Nkon NEFs so well that it's worth the little bit of extra effort. I use CS3 for special stuff like HDR image creation or making panos.