I was lucky enough to get a preview of the clock in operation about a month ago - guided by the clockmaker himself. Two things stand out in particular. First, the sound. The clock has a really satisfying mechanical whirr and clunk. A satisfaction that you just don't get by building software! Second, the LEDs. Bright blue LEDs mark out the hours, minutes, seconds. and they do so with sweeping movements across the clock face. These sweeping LEDs are exactly that - LEDs that sweep. It's not an array of LEDs that get turned on-and-off around the face, it's just some LEDs on a bar that is swung round mechanically.
Come and see it next time you're in Cambridge. It's mounted behind bullet-proof glass on the wall of the bank. There's even a special audio system so that you can hear the 'tick'!