Vi Winco is a low quality window which means your assumptions are correct. Okna is a much better window in so many ways ; energy efficiency, looks, engineering. The list goes on.

There is a reason why your roofer showed you Vi Winco. Most uninformed " cheapest price" contractors will offer the lower end windows such as Vi Winco, Reliabilt, and Alside.

Your assessment is spot on. I know I am repeating what the above gentleman stated but just to help drive home the point.

No need for any advice from us Alison, you sound like a pro that has been there and done that! Well done.

Which Okna series were you comparing it to?

Even Okna's lowest grade product is mile better than anything ViWinco.