Most of the Ploopy trackballs are designed for fingering(!). The one shown in the article looks to me like the Adept model which I have too and is not a thumb-d

Most of the Ploopy trackballs are designed for fingering(!). The one shown in the article looks to me like the Adept model which I have too and is not a thumb-designed one. (My Elecom left-handed wireless trackball on the other hand is a thumb-oriented one. They take more getting used to as thumbs aren't quite as dextrous)