The reason that I want to download and them delete my cards is so I can use this type of device to substitute for the many cards I have to carry. Because of the type of work I do, I shoot quickly and I bracket a lot. I only use RAW and I can fill a 4 gig card in less than an hour - sometimes in half an hour.
Jobo make a similar device that has a small screen for viewing before deletion, something this device doesn't have. However, I have read a number of posts in various places of people complaining of file corruption with the Jobo, so I'm staying away.
I know that deleting files without actually viewing them can be potentially dangerous, but I would only consider doing so after testing a device for a while. Still potentially dangerous I know, but at what point do you draw the line? Many people won't use 4 gig cards in case something goes wrong and they lose their images. but for me the compromise is to use 4's rather than 8's or 16's, which I would prefer to be using.
While I do consider things like file corruption etc., I don't get too anal about it. Everything's a bit of a trade off and where we draw the line for our comfort level is a very individual thing.
Anyway - anyone bought this thing?