For me (and I must emphasize that this applies only to me, your experience may vary), the current combination of the Dunlop D404 front and Riken Raptor ZR 225/55-16 has worked very well. I am much more confident in the stability, traction and braking capabilities of the Riken than the stock Metzler.
The Riken has given me over 22k miles with no issues whatsoever. It looks good for another 20k.
I originally ran the Metzler front tire with the Riken but it proved to wear very quickly, especially feathering on both sides. This may have been due to not running enough pressure in it. Given the negative experiences that I had with the Metzler rear, I was happy to move on to something else.
The first Dunlop D404 lasted about 11k miles but I replaced it early since I was about to embark on a 4000 mile trip. The current is the 2nd Dunlop and it is still running well. I've never had any type of grip issue. It also seems to handle the rain better.
Those are my thoughts. Depending on your riding style, you may or may not be a good candidate for the darkside.
