Northern Comfort was very good from a sales perspective. They sold us on the quality and benefits of their manufactured windows and doors, but that was the ONLY thing they have done well. On our order of 8 Windows and 3 doors to be replaced and installed, it took them 8 months to measure and re-measure our windows and doors twice only to deliver the wrong sizes for ALL of them requiring them to be returned and re-manufactured. 1 more month for the right sized windows (mostly) to be installed. The 4 man crew we were told were installing them (their best) ended being a two man crew where only one guy did any work, and the other was unable to communicate in English or French. It is now 10 months and we still do not have our last door installed, and they are yet to replace one of the other doors that was damaged prior to its installation. We still have trim off one of our windows because our "4 man specialized crew" couldn't replace it since the window measurements were STILL not completely correct.
I hope others have had a better experience, but none of the friends or clients I have spoken with have been satisfied with their work or customer service.