ebay chips if you like "cheap", but if it goes wrong, does the ebay seller or tuner have a
garage you can pull your car into for diagnostic trouble shooting if the chip causes problems?
no they cant, hence cheap, and you get what you pay for
I have been on here for a some time now, and seen it happen all too many times people, mostly newbies stating their car is running awful or rough, due to some unknown tuner or ebay chip seller.....and it always ends in the same thing, being told to go to a proper and well know tuner with a good reputation who has that level of aftercare
up to you, but if it was my pride and joy I sure would be taking it to an experienced tuner who can offer support in case of any issues i.e. AMD or Custom Code