I have one that I use every now and then. My main reason for using it versus my laptop was for dive trips when I didn't want the laptop on the boat but needed to clear the card between dives. Now I just bring enough cards with me for a couple days' worth of shooting and use my laptop as the backup/offload. I almost always have my laptop with me anyways, so it isn't a big deal for me. If you travel without one, having another device to offload the images onto isn't a terrible plan, though it isn't cost effective unless you really are shooting 20+ GB on a trip. That isn't too hard to do these days, especially if you shoot RAW on a newer dSLR, but below that point the price justification isn't always there.