I have a PSD file with an embedded .eps logo. When I export to Photoshop PDF and zoom in, all the text and shapes look very smooth, but the Smart Object .eps ends up not retaining its vector status.
When I double click the .eps smart object in Photoshop, the preview that loads shows me that it clearly is vector (I can zoom very far, and it'll be smooth).
However when I embed this in Photoshop and export to PDF, no dice. I've also tried with .ai and .pdf versions of the logo.
I am using Press Quality on the PDF export settings.