Roughly two back tires replaced for every one front tire. Most of my wear
seems to be from accelerating hard out of corners-- it quickly rips the edges
off the side grooves on the rear tire. For bikes in general as power goes up,
rear tire life goes down

. Not a big surprise there! If you can feel your
front tire squirm under braking, it sounds like you are doing some pretty serious
track-type braking on entry. On most of the rural roads around here, the
surface is pretty sketchy, with intermittent debris and such, so I tend to get
my braking done early and do the slow-in, fast-out routine. With my history
of mostly dirt riding, I don't mind the back stepping out-- but the front, that's
another story

. I "chirp" the front tire occasionally under hard braking,
but once turned in, it's just too easy to tuck the front with all the crap on
public streets. For me these Hypers are just too expensive and too pretty
to be low-siding them in a gravel patch! Maybe if I was rich and about 22 (is
anybody rich at 22?)...
As far as tire mileage... most of the new soft-compound and multi-compound
supersports tires are done in less than 3000 miles of sport riding (more if you
spend time just commuting on them). 3000 miles = 4800 km.
YMMV <-- always wanted to say that...
BTW, the new Sport Rider mag has a tire comparo. Seems to favor the
Bridgestone BT-016 and the Pilot Power 2CT. The Diablo Corsa III and the
Dunlop Qualifier were also highly rated. Two testers rated both street and
track on a GSX-R600 and a Kawi ZX-10R. See April '09 issue...