Hello,
Depending on the size of the page and the details, rasterizing every page into an image using the PDFDraw class may take time.
Since you are experiencing issues with fonts on different systems, it is possible to use our Optimizer class to embed and subset the fonts into the PDF, so that rasterization will not be required. This process has the immediate advantage of not needing to rasterize the document.
Please see the sample code here on how to use the optimizer class
Here is a forum post on how to use optimizer settings to embed fonts so that they work regardless of where the document is opened: