I had bridgestone bw previously on my dl650 k6, and they lasted 18k kms, then I started using metzeler next, and they lasted me 23k kms then I replaced them with other next tyres, and then I sold the bike..
Now with my new Vee2, I think I will replace bw by metzeler next or by the new Michelin pilot road 4 trail, it depends on price..
I still have few kilometers on my bike to say how much bw will last on it!
My usage is pattern is 60% straight roads (I use my bike to go to work), 35% curvy roads, and less than 5% white roads..
I usually replace tyres very flat on the center and good on sides, so bi-material tyres are better for me.