The Vertical SBX 24-Button Digital phone is the most commonly used on the SBX system because you can not only program all of your line appearances, you may also program the unused buttons for DSS/BLF. This is extremly useful in the business environment to see when your colleagues are on the phone and call them at the touch of a button.
The handsfree speakerphone has excellent quality and is used for Call Announce type intercom as well as dialing on hook and even completing the conversation. The speaker is also used to receive paging and we meet me feature you can pick up a page and talk as an intercom call.
Face it, Americans love phones with lots of buttons, and this phone definitely has lots of buttons.