Now that I have upgraded RAM for my MacBook from 2Gb to 4 Gb (max for MacBook) makes a real difference in speed and stability when using Aperture 3. I wouldn’t believe the difference is so significant before I installed the new memory. After this upgrade I have been a full time Aperture 3 user. I have tried to learn a lot how to effectively use curves tool in Aperture and especially how to use multiple curves adjustments locally (by brushing them in) to improve the tonality and colors in a shot. I think I have taken a big and very crucial step forward with Aperture. Now I am starting to feel “home” when using it. So, if you have speed problems with Aperture 3, upgrade the memory, it really has a big impact!