What the POSSIBLE difference is between a GT1 or any scan tool purchased from an authorized dealer and ebay is usually the assessory contents, the physical condition of the diagnostic tool, but most importantly: the update version of software currently installed. Updates could potentially mean getting the job done or not at the cost of $750-$1200 PER update, with the difference being the ability of the diagnostis tool to initiate adaptations, be programmed for bi-directional communications, or even the simple ability to handle specific protocol language. I personally own a GT1, MODIS, and Genisys, and there IS a difference of information available to any specific problem present between the 3 units.

 

I am planning to open a BMW service house together with my friend who is now working as a mechanic at BMW Service Dealer.
That's why I bought the GT1 scanner...
I tried to use it and I think it is working just fine.