I doubt whether anyone will believe this but I changed my front pads to Brembo sintered pads on 33,000 miles. I have just clicked over 79,000 miles and there is still a couple of millimetres there. My front discs are now on 4mm so I will probably replace the discs and pads whether they need it or not at my next service which is about 4,000 miles time.
Out of interest, I have replaced the rear pads twice during this time. Also, I tend to use the gear box to wipe speed rather than using my brakes. I am the same with my car.
Sorry, just noticed, this post was intended to be in response to AndyLP's post of sometime in 2016 - it was at the foot of the first page of this thread.
. Smileys don't work for me either - supposed to end this paragraph with a line of embarrassed faces ...
Cheers for now,
Tony