A comment
Installed in a country house, plastic windows LG 700, given the harsh winters, all the windows were with double-glazed windows. I did not save on accessories (as others do and then overpay) I ordered the original one - Roto NT.
After installing the windows, I noticed that in the kitchen they open much easier than in the hall (most likely, the installers and the manufacturer twisted something). In addition, he noticed that one of the windows is constantly “flowing”. I started to find out the reason, it turned out that the ventilation hole did not function correctly. The air practically did not go out into the street, but on the contrary pumped from the street into the room. I put a good range hood and the problem disappeared!
I am very pleased with the windows - the thermal insulation is wonderful! Noise isolation is just not overjoyed!
I advise you, if you are going to install these windows, when dismantling the old ones, control the installers so that there are no old wooden spacers left. If they stay, it will be terrible to blow through them.
pros
no blowing, soundproofing “like in a tank”.