I got one of these card readers free with a transcend SD Card I bought, I already have an SD card reader built into my laptop, and a usb 3 5 in 1 CF/SD card reader, so I decided to compare them.
Card readers are quite unglamorous objects, they're very functional and I think unfortunately the transcend SD card reader is the worst of both worlds- the best card reader I own is the one built into my laptop- it's always there, takes up zero space, just plug the card in and off you go. The fastest card reader I own is the usb 3 SD/CF reader, it's about twice the size as the SD card reader but when it's in the bag it's a negligible difference- so that leaves this transcend rdp5, functionally it's the worst of the lot, it's so small that it's easy to lose/forget, if you need to use it and you've left it at home you're out of luck.
In terms of speed, the USB 3 reader is slightly marginally faster than the usb 2 reader, which is marginally faster than the built in reader (negliable difference). I was testing with a class 10 SD card though, which is pretty zippy but not really fast enough to even saturate a usb2 connection- so with faster SD cards in the future (or using a fast CF card) you notice the difference between usb 2 and 3, but with most cards you won't notice, so don't think you need usb 3, although it might be useful in the future.
Build quality is fine but far from exceptional, its mostly plastic and about the same level as a usb memory stick- the lid comes off and can be lost, so be careful of that
In summary get one if you have no usb reading facilities, but if you have a reader built into your computer/laptop that will likely be just as fast and more useful- and if you're looking to transfer photos from a camera then check that you can't just connect the camera to a computer via usb to transfer photos that way