Now that I'm approaching 8,000 miles on the Exedra and our riding season is winding up due to cooler weather, I thought it worthwhile to pipe in again with my 2 cents worth.
I have to agree with evil Mitch's assessment overall, except that the observations we share in common are differentiated by my results being reported in miles traveled and not, as in our esteemed Aussie reporter's case, in kilometers. Naturally, the other big difference between our experiences with this tire are the riding conditions, most notably the difference in ambient temperatures over the course of our respective riding seasons (his being year-round, mine being about 7 1/2 - 8 months long). I believe that it's fair to assume that we are both aggressive riders. For the record I should note that I never perform burnouts, but I do spend more time than many riders in lower gears (for the added power instantly on tap as well as for the modest engine braking that doing so affords me) which does lead to harder braking at times with the associated tire wear that such bad habits also cause.
As for the other big variable, i.e. road composition, who knows? From the sounds of it, though, that may be a contributing factor, too, along with the generally warmer year-round conditions to be had down in Brisbane vs. here in New Jersey. Such things would account for the roughly 2k+ or 1300+ mile difference between his and my results.
As I had mentioned in an earlier post, I began to notice substantial center tread wear as I approched the 7,000 mile mark, a milestone by which the Metzelers I had used previously were totally shot. Now, with about 8,000 miles of usage, I can say that the tire is still serviceable, but I have had to become much more conservative when it comes to pushing the envelope in turns and through the twisties. If I were soley concerned with maximum performance all of the time, I'd probably pull the tire now or within 500 additional miles of usage and replace it with the same. As we are approaching the end of our riding season here, I will choose to push the beast a bit more gingerly and brake a bit less forcefully, as one needs to do anyway around here this time of the year, even with fresh meat, due to the aforementioned
30 to 40 degree drop in the ambient temperature of the local roadway surfaces, the fallen leaves littering the roads, different relative humidity and dewpoint levels, more roadkill etc..
This tire will provide another 1-2000 miles of reasonably safe and sound service before it reaches the equivalent point at which I would have replaced the Metzelers I had been using previously. Therefore, all other things being equal, I will claim that the Bridgestone will likely deliver at least a 30% (9,000 miles) better useful lifespan than the Metz provided and very possibly a bit more. Until something better comes along, I'm sticking with the Exedra, which also happens to correct our speedo deviation as a welcomed bonus. As Mitch mentioned, the wear pattern is markedly more even across the entire tread pattern and that is another big plus. Again, just for the record, my chicken strips are about 1/8" wide on both outer edges of the tread or, in essence, they are negligible.
N.B. as of 3/10/14: I pulled and replaced the tire early the following season with only another 500 miles of usage and with some cord showing. All in all the tire gave me about 15% more mileage than the Metz at about 70% of the price of a Metz, so, overall, IMO, the B'stone is a better behaving and significantly more economical tire!