The Fibrex cladding is the same material used to make Trex outdoor decking, so Andersen has confidence in the durability of this product.

I'm the service technician for a dealer selling the A Series since 2008, and I haven't seen any problems with the durability during that entire time. Unknown to many, they've also been using Fibrex on the sill of their TW line for over 20 years, and it's been great as well.

Personally, I still like the 400 Series better overall-it's a very proven product around since the 1960s. Plus-it's now available in most of the colors of the A Series. The only downfall I can think of is that you can see a small strip of the exterior color of the sash on the interior because of the vinyl-wrapped sash. Which to me is a compromise for having a maintenance-free sash that's cranked open into the elements sometimes.

Hi there. Thanks so much for your comments and advice. As it turned out I had a choice between two high-end products: Andersen A-series casements and Marvin Ultimate Casement (aluminun-clad), both priced about same...Marvin a little higher. ...I went with the Marvin.... I understand either way I went is a good choice.

Sounds like a winner either way, I'm sure you'll be happy for many years!