I love them. We tend to stand hunt, so they're closed on the way out to the stand and when I get settled in, I open them. If I see something, it takes less than a second to have them open and the glass ready for use. They keep windborne dust, snow, rain, or any plant matter off the lens. They keep the lenses clean during storage as was mentioned earlier. It's a personal choice of course, but I have them on all my glass. I haven't seen the weaver covers and I don't know if anyone in the GTA sells them, but I've not had any problems with the Butler Creek covers. There, my 2 cents worth.