I personally always like them open when coming in to land - I don't much like a landing without being able to see where we are, but I also don't like bossing other passengers to open theirs (although I have done when it's been a rougher landing!).

Today the WT+ cabin was a mass of closed windows and pax too absorbed in the delights of their day-old Hate Mail On Sundays to notice we were coming into land... fortunately with a bit of neck-craning I was able to see out of the one open window.