Windsor anything is in my opinion not a known quality product. Between those, no choice there E Series A. Marvin Ultimate or Kolbe would be the first two choices, then Loewen the E series, just .02.......

Personally always go for the concealed jamb liner in my opinion. Why are you not considering Marvin or Kolbe? They are better windows.

The supplier we're working with also sells Kolbe. He indicated that the Windsor has the same construction methods (e.g. extruded aluminum, AAMA 2604 paint, etc.), but that the Kolbe windows are "more technical". I also understand that the Kolbe windows are at least 20% more expensive and that the Marvin windows are even more expensive than Kolbe (and very difficult to get parts for the Marvin).

"Windsor has the same construction methods"

Doesn't mean its any good. He may get a better discount and make more money on a commission. I haven't done anything retail residential in 15 years, had opportunities to sell Windsor and would not as they are a poor product in my opinion.

What makes them a "poor product" relative to, say, the Andersen Eagle series?

After extensive research we decided on Marvin integrity wood/ultrex. This was our single most debated and best informed decision of our entire build. Just weighing in on our experience with this very difficult topic.

Performance Values, Fit and Finish, Customer Service (when I sold), Durability.

Equanimity - So as to balance this conversation, let me tell you a little bit about Windsor Windows & Doors. Contrary to the comments from a few frequent forum posters, there are many architects, builders and professionals throughout the country who like and repeatedly recommend our products.

Windsor windows and doors have been installed in some of the most magnificent homes throughout North America, including the Bighorn Ski Chalet at Revelstoke, British Columbia, which was named the Best Ski Chalet in the World in 2014.

Windsor started as a small, custom window company in Des Moines, Iowa in 1946, and has been a part of Woodgrain Millwork -- a family-owned company and one of the largest millwork operations today -- since 1987. Our relationship with Woodgrain is one of the reasons we are able to offer one of the best values in the industry.

Through the years Windsor has continually evaluated and improved our products. We strive to be easy to do business with through open, honest communication with our customers, accountability for our actions, and by conducting business in a respectable manner. Our mission is to deliver exceptional value through the relentless improvement of our people, processes, and products.

Our windows and doors meet the same rigorous standards set by independent testing companies as other window manufacturers that display the American Architectural Manufacturers Association (AAMA) sticker, and meet or exceed the specifications put forth by the National Fenestration Rating Council (NFRC).

For more information, I invite you to check out our Houzz Ideabooks and Projects that feature work from builders, architects, and designers across North America.