I'm running this tire on my DRZ400SM on the rear and it's amazing on the street. But the story changes once I hit the dirt, but you have to expect that from what basically is a street/rain tire. Speaking of, I've been caught in the rain a few times with this tire and it hasn't given way at all, even hard cornering on wet roads.
These come mounted on the new 690's... that should tell you something. I tried many combinations and brands on my 08 690E and the MT21's are hands down the best for DS. I have ridden the CDR and COBDR with these tires and would have no other. Plenty of miles left in a set after either of these treks. Some brands make the front end squirrely at high speed, but not the MT21. They are quite good on the road at any reasonable lean angle.
So far, I'm 3,000 miles into my first TR-8 front and I'm impressed. Excellent traction both on and off-road, wet or dry. Running on a Husqvarna TR650, it looks like I'll be getting at least another 3K miles, easily. Only negative I've found was it took a bit to balance.
I had no problem with this tire other than it didn't last long. I ride a Triumph Street Triple R and use it mostly for touring. I don't remember why I got this tire (must have been really cheap) because I normally use ContiMotions. I have gotten over 14K on the Conti's and almost alwayd over 7K. These were about gone at 5,200. I probably could have gotten a few more mile (no steel showing) but I was on a trip and didn't want to caught in the middle of nowhere with a tire out.
I bought these tires to replace my Shinko 244 for mostly street use. They work great. I lined up the dot with the valve stem and they ride really smooth. I will buy these again if they last for a while. I have them on a DRZ400sm with 18/21 wheelset on. I like the way that they can switch between pavement and light off road with no hiccups. Urban assault tires all the way!!!!!