Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Convenient, but can't power/charge some devices

I purchased this hub for the convenience of having a card reader and usb hub, all in one. It works fine as a card reader using Mac OSX. Cards show up on the desktop and transfer speeds are acceptable. I use an external bus-powered hard drive (2.5" 5400rpm), and it will not spin up if connected to this hub, even though the hub does have its own power supply. I've also had no luck charging my Garmin Forerunner 205 GPS watch. If these things are essential to you then I'd recommend trying another approach. If you're content using thumb drives, media cards, and devices that don't need to be bus-powered, this seems like a nice solid device.