The difference is that the one you have listed is compatible with older versions of VAG-COM/VCDS. It should probably work with our VCDS-Lite package which you can download and try for free. You have to have the USB driver for the cable. They have posted a copy of VAG-COM 409 in their listing - clearly against our copyright - but I do not see the driver information there.
The free shareware VCDS-Lite can be down loaded from our web site. If you get it to work properly, and remember, it does not support 2006 and newer vehicles, and if you decide you would like full DTC descriptions and full capability of the VCDS-Lite package, you can buy a license from Full VCDS-Lite in our Web
store. We do not provide licenses for VAG-COM 409 any longer.
The other main difference between our interface products and the one you list is that ours allow you to run the current full version of VCDS giving the most complete factory level support for all electronics in 1995-2011l VW/Audi/Seat/Skoda cars at its price performance level in the market place.
Is it for everyone? Probably not - which is why we offer the VCDS-Lite product.