It's huge. We're talking largest Apple Store in the world, by square footage. The store, in the city's historic Back Bay district, looks like a four-story glass cube. It's the first store inside Boston proper and the first with (finally) easy subway access. According to a store employee, it's a good thing Boylston Street is so big: Apple estimates 1,500-2000 customers/hour will visit — more than 10 times the 160/hour that the average store gets.