Not a full winter, but got most of last (installing living room windows in -15C is interesting). While of course it also reduces sun heat during winter, the sun is low enough during the winter that we only get maybe a couple of hours at best per day of sun. Given that most of the winter is cloudy or overcast to some degree anyway, we didn't notice the little heat we missed due to the IR film.
On the flip side, the glass we replaced was some 20+ year old two layer glass while the new were thick 3 layer stuff. They're vastly better insulating (heat and sound), so that alone was a huge plus compared to the old.
On the flip side, the glass we replaced was some 20+ year old two layer glass while the new were thick 3 layer stuff. They're vastly better insulating (heat and sound), so that alone was a huge plus compared to the old.