Does it run on Windows? If so, could you try to boot some kind of Linux distro from USB, to see if it's similarly bad? I'm very suspicious of the driver because

Does it run on Windows? If so, could you try to boot some kind of Linux distro from USB, to see if it's similarly bad? I'm very suspicious of the driver because my T530, which has by a huge margin the most atrociously (physically) uncomfortable touchpad I've ever seen, has that problem too. And any other Windows-running laptop I've used from any brand, too. My T61 on the other hand, runs on Linux and the touchpad is super smooth. It's not only Apple. Could be just Windows drivers being poor. :)