I have run Metzelers since I started riding (2yrs). A set of M3s came with the bike and I upgraded to M5s as I progressed.
These tires are great in dry and wet weather. They heat up pretty fast.
I got caught in a Denver down pour coming through the mountains and had no issues. It was my first time in rain ( I'm from CA).
These tires are a good street and track day tire. Depending on how hard you ride, you could do a track day or two and still get some decent mileage out of them.
This is a street/track tire, so you will get decent mileage, but nothing close to a touring tire. And it depends how you ride. Usually will run a front down close to 8-9k and a rear 6-7k...more or less, depending on riding.
When these tires wear it has a noticeable wear pattern. And of course this will affect the handling.
Metzeler is owned by Pirelli and the first few sets I got were made in Germany, but my last set were made in China. So far, no issues.
The new M7RR are out and I will be looking to get a set as these wear down.
For deals also check out bikebandit.com, usually have good deals and ship for free and if you like Revzilla instead, they will price match it and ship for free pretty fast.
cheers!