curtain cornice box or not?

With a crazy weekend and week ahead of me, I am in a super hurry to get my apartment decor all put together...

I have a wedding this weekend, guests that I am hosting and so many events next week for fashion week, my calendar is looking like a coloring book. Sigh.
So one of my personal necessities is to finish my windows (they are the eyes of the home, no?)
I have beautiful drapes that hang and cover my windows, but I am absolutely in love with the tailored look of beautiful cornice boxes to match. So polished and glam...which must mean I need to have one too. I think my favorite are the ones with really fabulous trim and detail, don't you guys agree?
a gorgeous mary macdonald room. die! 
I especially love this flowy valance...