I did a small experiment and ordered a couple of my favorite photos as 4x6 prints from Apple. They arrived today! First, let me say that these were relatively cheap at 50¢ a pop for 4x6s. The photos were shot in Adobe RGB so I had concerns over color proofing. Now, the Apple photos had a pretty good color match to what I saw on screen. It was a little warmer than the digital file, and especially on contrasty areas the photos look somewhat foggy. I see the contrast issue as a byproduct of going from RGB to CMYK, but the color cast is purposefully done by Apple. To be honest it's not very noticeable unless you have brownish highlights which might appear warmer in the print than the photo. At first I thought my lens had something wrong with it because the prints looked as if all the edges had a massive amount of color fringing, when actually the Apple prints just couldn't handle the amount of detail present in the photo. This is probably from the reduction of size. Apple does try to remedy this by boosting contrast on the edges. Overall I'd say the prints are very good, good for the convenience it provides as you can order directly from Aperture itself.