We watched this double bill at the Southampton Cineworld and, like others, it was only about 40% full. Maybe people were put off by the length of time. One or two left during the short interval.
My wife had read the Millennium trilogy but I hadn't and had no prior knowledge of the plot(s). However the end result was that we really enjoyed both films. The sub titles were a surprise to me but I managed to keep up and they didn't detract.
I wonder how different a Hollywood version would be.
Cheers
Chris