For what it's worth, i've dropped my 650 3 times onto floorboards, carpet-covered conrete and a thick rug... no hassles.
I just got back from a camping trip where i forgot that the reader was in the side pocket of my patrol pack and it got thrown around, sat on, dragged through various areas and had beer spilled on it.
Looks like new. Works like a charm.
Seems tough enough... or i was just lucky.