Really, all these devices are functionally very similar. But you do have some variation between those that offer secure and non-secure areas, so users need to be wary about how they use them.
People can mistakenly assume that deleting files on their encrypted device permanently removes every trace of the file. The differences between just six products in this review shows that secure devices can be just as vulnerable as ordinary USB devices. Our advice is to choose an accredited product and use the device responsibly - never lend it to anyone.