DVD final quality?

I just completed a 45 minute HDV video and authored it using DVD Studio Pro 3. It looks good and plays well. I have the following question:

If I want to release just a few duplicated copies prior to replication would the quality be better if I burned them onto DVD-R directly from DVD Studio Pro as opposed to duplicating them using a duplication program such as Fast DVD Copy 4?

I assume that by going the Fast DVD Copy 4 route I will be re-compressing and thus lose a little quality. Is this a correct assumption?

Thanks for your assistance.