First sign of trouble was when installers forgot to close the hole where a vent was taken out. There was an impending huge downpour that night. Very difficult to get in touch with service people to have the hole covered.
After installation, singles were blown off the roof during a thunderstorm.
After 7 years, there were signs of problems with the roof shingles. Again very difficult to get in touch with service people. They are passing on the problem to BP, the manufacturers of the roof singles. Did not even send somebody to check if it was the installation or the material.
So far in my experience RONA seems to be the best in after sales service.