The back of the device shows us why external power is needed.
As you can see, it's a four-port powered USB 2.0 hub. A cable is provided, which will plug in to any available USB port on your notebook. With this in place, you can plug in a keyboard, mouse, printer, or even another USB hub (should you have too many devices).
Here it is in use. I was using a particularly high chair, hence the angle.
I found the overall experience with the Port Ergostation pretty good. Having an adjustable height of the notebook display made a huge difference to my working ergonomics. With a USB keyboard and mouse connected, after a while, I completely forgot I was even using a notebook.
The first thing I started to miss, was port replication of RJ45. However, there is always the option of using wireless, or in fact a USB 2.0 Ethernet adapter. Of course, once you've plugged in an external hard drive and DVD Writer, you might start to find yourself being bottlenecked by the fact you are sharing the bandwidth of a single USB 2.0 port though.
Other docks also have replication of displays. This is useful, as you can have a second display constantly plugged in to it. Then by docking, you can have two displays at your disposal.
This is an excellent dock and it's universal status makes it a good investment. If you have several notebooks, or change them often, it makes sense. At £44.99 including VAT, this is quite a lot for what is essentially a stand and a USB hub. However, compared to the official notebook docks that tie you into a brand, it's not very much at all.