I have now had the windows from Fieldstone for 8 years and already the trim on every window has cracked where it is attached to the window frame.
The insulation is likely non-existent. The breeze that comes through the window frame of every window can almost blow a candle out.
I tried getting them to come out to my place in the winter (2016/2017) to review the situation, but they stalled in 2017 to the point where it was no longer beneficial to test the windows. They used the excuse they were training a new person.
Now this year when I want to have them out, they doubled the service fee and will charge kilometers. And again they are training a new person.
If they were so sure of their workmanship, they wouldn't be charging this high rate. They only offered a 5 year warranty and for good reason for them.
I would not recommend them at all to do your windows. I included a picture of the trim so that everyone can see how it is separating from the frame. Sorry, I cannot show the candle blowing in the window from the lack of insulation.
Update Feb. 2018
Ken the owner called and came out to inspect the previous work and found the insulation had not been properly installed. Within the next business day they had a repair man out to our house. He checked and repaired all the windows that had issues.
The work was done extremely well. All windows are now sealed tight and we no longer have a draft coming in.