I've got to be honest; the only busway I've ever used is Fastrack around Bluewater. The service there seems efficient (surprisingly so in fact) and the route is well maintained. But on the flip size, the nature of Fastrack is that it seems ideal for an operation of its size - i.e. a couple of medium-sized towns in close proximity to a prominent non-central location with parking issues. And I would argue that this is the ideal scenario for a busway, not that of Cambridge.