Yep, I'm not a fan of metzlers either mate, I had 'em on most of my BMW's and I found that they tracked all over the place, slid on wet white lines, followed road contours, and if the road had been "scoured" in preparation for a new layer of bitumen, it was downright dangerous.
I binned them and replaced them with just about anything else, and they were better. Interestingly I've got them on my Trumph Rocket III, and I've had no issues like I've described above. Even with 7000 miles on them, they're only slightly worn, (I was originally told that I'd probably have to replace them at 5000 miles, which is "normal" for Rocket III's) and should be good for a few thousand more. Horses for courses? Cheers, Terry.