always best to render using specs that match your source, so when you say you imported DV footage and now you want to render to 10 bit uncompressed, why?
If your DV footage was DV25 or DV50 at 720x480, rendering with 10 bit uncompressed is a massive waste of drive space, you will be going from 25 or 50 mbps to 200 mbps with no increase in quality from your original footage. The 486 vs 480 is not a right or wrong, best or better issue.
They are just older pre vs newer post digital era, systems of 525 scan. So again, it matters most what your source footage is, and to match that as close as possible throughout the entire work-flow.
Hope this helps.
Paul Buhl