I have about 1200 mi on the odometer. After about 300 miles of highway riding in a week, I was surprised and pleased to learn that the bike is perfectly capable of doing a sustained 65-70mph. (I didn't push it higher, but I think it could have gone a bit higher than 70.)
When you're cruising at 65-70 you don't have much pickup, so I wouldn't do it in situations where there's a lot of merging traffic and so forth. And if you drop off the throttle to let someone in from the right, you have to peg it to get back up to 70. But it is doable.
When I'm riding at high speed it's not the vibration that bothers me, it's the headwind. If there's much wind, my body is like a sail and my large full-face helmet is jerked around. It's not dangerous, it's just annoying and uncomfortable. (I'll post video of my ride over the upper deck of the Verrazano Narrows Bridge and you'll see what I mean.)
Just like everyone says, it'll go faster when it needs to, but the most comfortable highway speed for this bike is 55-60mph. It was beautiful to ride on fresh blacktop on I-295 in South Jersey at 60mph on the right lane, with cars passing me at slightly higher speeds. I could have done that for a hundred miles.