The engineering behind the 16th edition PDF is superior. Many older editions weighed in at 200MB+ because they were just image scans. The 16th edition is often optimized (text-recognized OCR) down to 30-50MB.
: High-yield points and mnemonics are highlighted throughout, with special summary sections at the end of the book. How to Make the PDF "Better" (Tips for Users)
to ensure you have the most recent high-yield facts and clinical patterns.