If you've ever typed on one, just seeing the picture instantly brings back the sound of the inter-changable font ball clacking away, not to mention the visceral feedback from the keys as you pounded on them.
The Selectric III pictured had several improvements over previous models. I won't go into them here, but you can read about them all at the IBM Selectric Wikipedia page.
This old school technology - which was quite revolutionary at the time with it's correction ribbon and stationary carriage - has been single-handedly responsible for every keyboard redesign since desktop computers were invented, at least when it comes to haptic feedback (for the haptic-ly challenged, it means using the sense of touch in an interface to convey information to the user - for example, if a key has been pressed).
They were big, clunky and loud, just like my high school girlfriend.
But like her, I loved working on it.