Tips
Having spent probably 15 hours researching how to make aperture run fast, I ended up with a new computer and a new workflow.
I was having the same problems, A3 was taking what seemed like HOURS to do basic adjustments to 5DII RAW files... I was working on a 2007 24" iMac 2.4ghz C2D 6GB ram 256mb graphics ,with the
library on a FW800 external. Slow as syrup.
Upgraded to a 27" 201 iMac 2.93i7 12GB ram with 1gb graphics, with the
libraries on the internal SATA 2TB WD Black 7200rpm and A3 on the internal Vertex 2 SSD.
The new hardware makes a world of difference of course, but I feel that working from multiple, smaller libraries makes just as big a difference.
Another thing- I found out that simply rating an image "9" or "x" does NOT delete the image. It simply brings it to a sub-library "rejected".
Turns out I had 30,000 rejected photos sitting around in my lone Aperture library. It took about an hour to delete all the rejected photos (after I went through my Albums and "rejected" all the non-rated photos).
I brought my Library file from 1.4TB to 800GB without losing any important stuff.
I then started to export all my biggest Albums (Weddings, events, vacations) into their own "Export as Library" Libraries onto my internal HDD. I deleted them from my "Various" Library after they were exported and confirmed. This took about an entire day to get them all out of my "Various" library as it IS tedious, but they all run lickety split now.
I now create a new Library for every couple/event/shoot and store it on the internal HDD. I have been using this new workflow for a few days now and it works great. Aperture 3 is now acceptably fast and it does not slow me down. It keeps right up
EDIT: Even when using plugins in 32 bit mode, it seems that my time spent waiting around for Aperture has been slashed by 70%. I spend probably a third, if that, of the time I did a week ago waiting for Aperture to make it's adjustments and show me the results.