I would have to say Tech Tool Store because its a proper software tool that has been made with an easy to use GUI interface. But that's not to say that GeGeek Toolkit does not have a place on a USB Pen Drive. Its going to come down to what you like best, everyone will have there own opinion on the subject. I think GeGeek has done a outstanding job in creating a tool for techs and is a lot of work to maintain the software. Tech Tool Store is well made and is packed with the tools that I find more useful when it comes to computer repair. But I am sure someone will argue the case for GeGeek, its not really about whats best for me, its what I would use and for me Tech Tool Store has the edge.
I think asking what is better is always a hard question to answer, its like what better Windows, Linux or Mac or Avast, Bitdefender, Eset etc etc everyone with have to own reason to use what they want.