You will only gain anything by doing this if you have a bunch of titles and graphics to rerender in 10 bit. DV is compressed at the time it hits the tape so rerendering in 10 bit does not magically make it better. Some will argue that digitizing dv over SDI into 10 bit will result in a better image. Some will argue that this is hogwash, I encourage you to find out for yourself what you think on that subject.
SInce you have already transferred from SUper 8 to dv, the 10 bit render is super unnecessary. Stick with editing dv unless you get a deck with SDI to try the proposed theory above, OR, you project is riddled with graphics and text, or you are doing anything except transferring 8 to DV. How did you do that transfer by the way?
In the olden days (pre quicktime 7), apple did not have a codec that supported hd color space, so blackmagic modified the apple codec to include hd color space for people that were working with HD years ago. Since apple has included the HD color space with the onset of quicktime 7, blackmagic has switched to using the apple codecs as the default codec. The apple codec if fine to use if you must, but DV should suit you just fine for this kind of situation.
In really simple terms 601 refers to the color space of SD video. 709 refers to HD, it a system of numbers that engineers came up with in the labs when staring at waveforms vectorscopes while doing math on an abacus.
Hope all this helps.
Jeremy