I have found both USB and FW800 slow in SL.
I had a scary experience the other day when I should ingest. The dialog box showed 1,4 gb of pix on my Sandisk CF card and when I hit Ingest, the box just showed for a second and then the card was empty !!
No pictures on it when I put it into camera, but it said 1,4 gb used info
Had to use Photorescue.