This type of staircase is less expensive than the rounded ("full radius?") one on our original plans. How would it look without the window seat? I imagine that the expense of adding in a window seat at the landing would offset any savings.
I like the idea of a coffee bar. Maybe not exactly this... but something similar. It'd be awesome with a sink and then closer to the door. People can grab their coffee and go. (although I guess they'll have their own little break rooms on the and floors.)