I suggest take a look at the ProVia Endure high grade vinyl window.
Triple pane is what I sell now and has very low U-factor and air infiltration.
I love their low profile slim casement window, just ... read more
Big +1 to Abe's feedback.
He is 100% right on the differences.
Inserts can be done very effectively with no weak links in the system in a vast majority of the cases. Where it really pays dividends to ... read more