I’ve optimized the PDF files for (nearly) all Lingualism eBooks. There should be no noticeable difference in the quality of images etc. in the PDFs. But optimized files are smaller and take up less space. Some files were previously 10 MB and are now under 1 MB. Feel free to re-download past purchases from your Account page if you would like the smaller, optimized PDF file.
You may notice on the Changelog on product pages that some audio files (including Anki files’ audio) have also been optimized resulting in much smaller file sizes. I will be updating the audio for more products in the coming weeks.