Rear:
The OEM 014 lasted 2000k's (Wood Screw) The 015 less than 1000k's (Hunk of Steel and a smashed carbon fiber hugger
).
The 016 got me to 16000k's and was brilliant from birth to death, and the 021 has been on there since and the bike will be ticking over 20000ks's in about a weeks time (and the Tyre still looks brand new!)
Front: The OEM 014 was on there for about 8000k's until It got a cut on the side, decided to replace it and be safe, put an 016 on then, and just replaced it about 6 weeks ago with another 016.
I don't wait until a tyre is bald or right down to the wear indicators, Because I commute on the bike every day I always fit good quality tyres with lot's of tread depth (helps with our summer Wet season and Winter rains/storms)
But so far the Bridgestones have served me very well (On 3 different bikes with nearly 80000k's of road work) Never found them to drop off in performance as they got near the end of there life.
Don't get me wrong, I'm not saying any other brands is worse or better, I just like the way the Bridgestones work.
Plus I find most stores up here seem to charge a premium price for Mich or Pirelli's, I assume they think "Premium Tyre, Premium Price"