I asked, since the "best" way probably depends on what the rows contain (i.e is there Shape data?).
However, if you are looking for a Python-based solution, I'm not sure how you would get away from using an insert cursor, which the cursor kinda being the "lowest level" operator available. Of course the new .da cursors (in v10.1) are much faster than the "old" cursors, so if you are running v10.1, that'd be the 1st thing I'd try.
If you were really handy, maybe you could use the new FGDB API, but that's above my head and I don't think there's a way to do it directly via Python.