Got round to taking some pics of my Griffin case:
It's not soft leather, it's a thin plastic case which is covered with leather (real). So it offers good drop protection too.
That's exactly what I went for (even comes with an OK screen protector). The plastic is a polycarbonate and while I haven't dropped it with the iphone in i'm pretty sure it's not going to spring apart like some of the cases i've seen I'm starting to think an Invisible Shield would be a better bet though as I could still dock it with the holder as opposed to lead only.