If you are a little bit like me you want to use the keyboard as little as possible while you are working in a graphic program. If you use it, you want to restrict the use of it to the usual shortcuts.
Sometimes it can be a hassle if you adjusting the size of your pen using the slider in Manga Studio. You still don’t want to type the exact numbers into the fields, do you? There is no need to do that after watching this 2 minute video.