A family of Microsoft presentation graphics products that offer tools for creating presentations and adding graphic effects like multimedia objects and special effects with text.
This probably won't be of much help to you, but I've found that even the best results from the built-in PDF export are not as good as what I get from using Adobe Acrobat. So I use Acrobat for all PDFs and get great results.
To get the best results using the built-in PDF format, check that you're not downsampling images by opening File>Options>Advanced>Image Size and Quality and checking Do not compress images in file. Set Default Resolution to High fidelity.
Then choose File>Save As. After setting Save as type to PDF, make sure you select Standard (publishing online and printing), then Save. That's as good as it gets!