Bought the roof about 5 years ago from NSR. When installed they forgot to install the roof over my back entrance which I had also paid for. They did come back to install but the roof leaks. As does a section on the regular roof.
Brought this to the attention of NSR before COVID kicked off an they said they would send someone out which never happened. Have tried a few times to contact them. Did get a hold of them once and was asked to send in an email with pics which I did with no response. They said they are under new ownership and have no record of previous interactions. If you are dealing with them I would keep it all in writing but given they don't respond to emails not sure how useful that will be.
Have called them at least twice onto of the email with no response after more than a week.
The roof looks great but if you want it to not leak I would go elsewhere given they don't seem to be interested in backing their work.