If you buy the full version of DocumentsToGo (word, excel, etc), it also comes with a very nice pdf reader that will allow you to zoom in very closely without the fuzziness in the stock BB pdf reader. Then you can avoid the rtf to doc conversion process. I think it is about $15 or $20. I've had it about a year, and it was a good purchase.
I have a BB Curve 9330.