I have that roof and find it flaps in the middle at the front while transporting it at highway speeds. It's to the point that a couple of the mounting bolts backed out and disappeared. I now run a ratchet strap over the top from front to back to give it a little downward pressure and stop the flapping. It could be because I have a windshield and/or back windshield as well.
That's not to say it isn't tough. I once strapped an Action Packer on the roof when I had to load a broken dirt bike in the back. After 70 kms of whooped out sand, there was no permanent damage or wear marks with just a sweatshirt softener between the Action Packer and the roof. Although I was glad I was on my CRF450 and not one of the people in the P5. I knew better than to go into the bush with a guy on a Husqvarna.
I would buy the roof again.