I would say yes, especially if you want the white interior. This would be additional savings not having to paint the 400. Fibrex seems to have a good track record.

FYI - The price difference for casements is minimal between 100 and 400.

+1. In the casement series, both are fine. I think you will like the look of the 400 series a bit better as it is a nicer line of window.

@toddinmn - I copy/pasted a comment below that was brought up in a different thread (https://goo.gl/4MZwkL) regarding the 100 series sills. I was leaning towards the 100 series until I read that comment. Do you have any insight regarding Andersen 100 vs 400 sills?

"...Before asking for opinions its always good to look at the manufacturer's details. The 100 has a poorly designed sill, if you can even call it a sill. There's no projecting bottom or drip feature to allow water to fall free of the house cladding. There's only an open joint filled with caulk that will eventually fail and allow water to get behind the cladding. I've seen it happen many times..."

The sill of the framing should be tapered and flashed properly regardless of the sill on the window frame. Almost all casements are like the sills in the picture. I am not sure about the caulking joint they are referring to.

I think what there showing is a picture of a 400 series double hung vs the 100 casement. If you look at the 400 casement it will not have a sill like that. That little drip feature will not do much if you trimming out the window.

Thanks for the info.