I've done some testing with the quality of export from Draw. I'm not absolutely wildly impressed with any but PNG and JPG seem to be best. Oddly, EPS gets bitmappier and so does GIF.
Note: The graphic was already shrunk once and reduced in quality; I'm just looking for comparisons between the four types and they all kinda seem to be the same.
Here's a file where you can look at the different files exported and inserted in Writer. I mainly looked at the edges of the thought bubbles.
The quality for those is fabulous. Extremely smooth lines on the thought bubble.
Unfortunately, you can't insert PDFs in a Writer doc.
But keep in mind that PDF export of lines is fabulous. If you have a Draw doc that you need printed as is, export to PDF if you need to send the file to others, don't export to the graphics formats. Just be sure to export with no graphics reduction if graphics quality is your main goal. Lossless Compression is the option you want.