GT-Boy:

Did this 170k miles include any track time ?  I had heard that 1 or 2 track days will necessitate a full PCCB brake pad replacement at Great expense.

The pads maybe (if we are talking GP style tracks with a lot of intense braking). The discs should last aprox 10+ of these events. Thus, if you do these track days often steel might be an interesting option in terms of cost. Drive feel and performance is bezter with Ceramics though.