Metzler Cruisetec vs. Avon Cobras

I don't like Goodyear either - from my experience with various 4x4's where they were the stock fitment. And they have zero experience of manufacturing performance motorcycle tyres, whereas Avon had decades.
Triumph's tie-up with Metzeler probably is a matter of convenience. They need a reliable source for their fairly niche large size and uncommon spec for the Rocket, and a big player was obviously the best bet, if nothing else because of the economies of scale. But I have every faith in Metzeler's expertise in tyre manufacture. They have a track record to match Pirelli. Though, over either I've generally always preferred Continental. I hope they will bring out a set of Contitours for the Rocket.