So far I've gotten 8-11,000 kms out of my rears and 15-18,000 kms out of my fronts. So I need 3 rears for 2 fronts. I went through the stock Brigestone BT56 and changed to BT020's in part because I needed a new year and the front was great, so I chose the same manufacturer and size, with a similar tread pattern.
My front and rear BT020's should both be ready for replacement next time around, and I'm considering a change to the Avon ST's.