Got a 1TB WD Passport
Wireless in for review. Comparing it to a Hyperdrive iUSBPortHD and a couple of other battery/HD/wifi/card readers (if no card reader built-in, then USB host port for a "dangly").
Short summary: it is probably the most affordable solution for in-the-field SD card backups, but you need to set it up beforehand to be able to just put an SD card in the slot and back it up. The entire interface is web-driven (meaning your device or computer must join the wifi network of the drive to change settings), which is different from other devices, including the Hyperdrive, which has an LCD screen with actual text. Of course, once set up, it just hums along happily, and WD makes the drives so the price of 1TB is very competitive.
Downsides include the lack of physical interface (aside from blinky lights and one button), requirement to be formatted ExFAT to automatically copy camera SD card contents, and slow (5-9meg/sec) copy speeds from a card. As an external drive, its quite quick (USB3), and as a wifi hotspot or streaming server, it is pretty good (although the Hyperdrive is faster in that respect). The battery life is also pretty good, but it won't charge other devices (like Hyperdrive, Ravpower, and others).
Meanwhile, I'm looking at these things specifically as portable, in-the-field memory card backup devices first and foremost, then as wireless servers for laptops/ tablets (to view images or download/ upload them), and finally as portable hard drives that might sit on a desktop. This may not be what you're looking for at all, but its the angle I'm taking.
Last edited by panoguy; 12-20-2014 at 06:03 PM.