It breaks down to this if you charge a Li-Po say Monday and use it Say the following Saturday if it's a good pack it's still going to be fully charged. Li-Po's don't lose charge Like NimH packs do.
As far as charge rate goes the only thing you'd see there is a slow charge time compared to a normal charge time.
Neither of the two questions are going to get you better performance. You'll see the same results either way.
Jason