Latest revision of this article still only pays lip-service to people who need a vertical mouse. The Logitech Lift is only for people with small hands and, the Lenovo Go is nothing more than an ordinary, conventional mouse, tipped on it's side, not a properly designed vertical mouse. There are numerous other options now available, including mice available in different sizes and both right and left handed, all completely ignored. I also note there is only one trackball.
Surely Sarah Jacobsson Purewal, you can try and do better.