I used to use an Epson P2000 when it first came out; in the field this was useful as it allowed a backup of either my cards, or a separate backup to what I'd downloaded onto my laptop to work from. In the case of the latter method, I would download a card onto my laptop, and whilst I was editing and captioning, the P2000 would download the same card as a second backup.
The problem with early units such as the Epson was that they were very slow, taking several minutes (seven if my memory serves) to download 1Gb. With the new Colorspace UDMA, in seven minutes you could download 14Gb!
Other neat things with the unit include maximum storage capacity of up to 500Gb, viewing of any RAW format, 2 slots covering 14 different types of memory card form factors and a battery which is good for 250Gb of downloading per charge. Pretty impressive stuff chaps!