I had the same issue as another purchaser; you have to spread the insulation and foil apart in the fixture base in order to be able to have the screws come through the mounting holes. With lots of fiddling, it got done. Remember to wash your hands after handling the insulation as per the instruction sheet. 
We put 2 of these in our upstairs foyer and they give lots of light and look great.
My wife is pleased (she chose them) that the shades are a white linen but have a light grayish tinge when the lights are on. We used Bright white LED bulbs (3000 K). We installed the glass diffuser with the frosted side down as it looks better than putting the shiny side down. And remember to try and position the base so that when you install the fixed drum shade, the seam on the shade is in an inconspicuous position. You can't rotate the drum once it's screwed into the base.
All in all, for the time it took to install them, we're pleased with how nice they look.