Since this discussion is now very long and old, the up-to-date information is quite difficult to find.
Therefore, I have created the same discussion with updated and current information, in the OS X Mountain Lion forum, at the follwing address:
Please go there for current information or if you have any questions.
I'm not sure what's going on but I feel like I'm taking crazy pills.
I've downloaded the filters and moved them to the correct folder and they're visible in Preview, BUT, when the file is finally exported and saved – it's bigger than the original file size! My original PDFs are exported from inDesign at 300dpi, and 200mb approx. Need them to be around 20-30mb without discernable loss in quality (they're magazines) and thought the filters were the answer.
Any help will GREATLY appreciated.