Understand never had to do a warranty with them just had good windows and no problems

My .02 on windows.
We built a new home back about 4 years ago.
Spent lots of time looking at windows.
Came to the following conclusions.

1) All the "top of the line" American made windows (especially Pella) are really middle of the road at best.
2) The best quality windows are made in Europe, look into Tilt and turn windows.
3) Triple pane windows are the way to go.
4) like everything in life quality costs more.

we ended up with windows from Canada, Fibertec, Fiberglas, triple pane casement windows. Not the best but every good if not better than an American made window except maybe for some small mfgs. Had a blower test done on house when finished. Before some small minor leaks we had 1.0 ACH.