I'm installing Mirage Rich Oak in Yellow Birch (engineered hardwood) in the living area/bedroom of my condo. My condo is 585 square feet, and about about 300 square feet is being redone (the rest is ceramics in the kitchen/bathroom/laundry space).

I'm having trouble deciding on the board width - 2-9/16" versus 3-5/16". The store said that typically smaller spaces look better with the narrower board size, but I think I'm more drawn to the 3-5/16". Any comments/suggestions on what might look good in the space?

I think either will look good. I would go with whatever you like better. I just put some 3 1/2" wide engineered Brazilian Cherry in a smaller condo and it looked great.