Yes, scan speed is important, it will be shown in the graph, so no need to care. The stardard in this forum is 4x for DVD.
For burn speed, sometimes, slow burning speed may give worse result.
Personally, I will record both for reference. It can help to see how speed affect your favourite media.
(My crappy 1213s@CS09 seems dead, it always give bad burn :a , otherwise I may post some scans for comparison)