Well I have 1000 miles on my Z8's and ........compaired to the BT-016's I had been running I have to say I like the BT-016's better. The Z8's are a good tire but are "twitchie" and seem to grab at ruts and bumps more than the BT-016's. I have to say I had a bit more confidence when riding with the Bridgstone BT-016's and think I will try the BT-023's next time around. The Z8's are good enough to where I don't feel like I want to change them out right away, I will run them till the wear bars are showing. (Cause I'm cheap)
I went with the Z8's as I was getting approx. 5,500 miles out of the BT-016's and wanted a tire that would get higher mileage and still perform. We'll see how the milage goes and I'll report back in time.
I ride some freeway, city traffic, and twisties here is Southern OR. The twisties are where I am missing the BT-016's the most.
I am not totally bummed with the Z8's but wish I had tried the BT-023's in hindsight.
Give the PR2s or PR3s a try (I'm cheap too so go for the PR2). Best tires I've had on any bike in any condition. They stick from the get go, are awesome in the rain, on the dry, offer great handling, and because of the different compounds I'd suspect you could get an easy 15000 miles on the front and a good 9000 miles on the rear. My mechanic owns a Kawa Concours (heavy beast) and he can put more millage then that on it. I now have winter tires on Versys after trashing the stock ones, but next Spring I know PR2s are going on the bike. I have them on my 570lbs MT-01 and the rear is still good after 7500miles. The only tires I tried that had as much grip was the Metzeller sportec M3s (back in 2009), and the rear tire wouldn't last 3000miles on my Speed Triple.
I have the 023's on now, 4k in, liking them a lot more than I did the PR2's. My PR2 rear was no fun at 4k. The profile went away and I had three flat spots instead of an arc.
The BT 016's were replaced by the S20's in the Bridgestone line-up. I had those on this spring and loved them but the rear was done at 3k. The front went 7k. I usually will toast the tires about evenly, and at about 5k, so the front really impressed me.
When I got the 023's I had ordered an S20 front and an 023 rear. My buddy who owns the shop "helped me out" by matching them up. Next time we'll get it right.
One thing we can all be sure about tires, is you'll find as many reviews as opinions Depending on the magazine, the winner often isn't the same. Some LOVE the PR2s, some have been disappointed by uneven wear. I went through probably 6-7 sets of PR2s, and was never disappointed once. I know some are in love with the BTs...and some aren't.
With that said, the best move you can make is replace the stock tires with just about anything else, you'll se an improvement in all departments