Well engineered windows of any type will do fine in your climate region. I have seen fiberglass, aluminum, or even vinyl. As a matter of fact, my Aunt has vinyl windows in her home (I supplied them) and they are doing fantastic in her application. There is a good resource in the DFW and Houston area that posts on here by the name of Randy (UltraWindows). He might be a good point of contact.

If you are looking at the narrower side of the spectrum in terms of vinyl, the glass loss will be negligible. Do you have storm windows? If so, a narrow profile window will likely fell larger.

Thanks, Todd. The Vytex quotes did include the exterior color of my choice My understanding is that the original trim will remain, but I may not be clear on the extent of the term "trim" The Marvin quote includes painting One additional issue is the upcharge for laminated glass on the Marvins--$500 per window. Is this reasonable? The Vytex quotes include laminated glass for 3 upstairs windows and any additional laminated glass is only $150/window. I think i would also like laminated glass for my 3 street-facing kitchen windows, so that is an additional consideration. Re whether it worth the money---I really don't have a sense of the aesthetic differences between them. I'm also concerned about reading that the Marvin windows only have a 10 year warranty on the wood, which seems to run counter to the claims that wood windows will last many years. Also, I can't find any air infiltration numbers on the Marvins. The U factor and other specs seem competitive with the Vytex.

A sash kit with Dual pane and low-E would have similar performance to a triple pane unit. The STC rating would be better and much less loss of glass over an insert. Installation can be simple to comlex depending on who is installing and the condition of the existing opening . I rarely see them installed correctly by pros unless they are somewhat specialized in these, the ones they got right were because the openings and window needed no modification.