Airport Extreme vs. Airport Time Capsule

  • Would there be any differences between an Airport Extreme with an external hard drive plugged in and a time capsule?
  • Granted that it's USB 2.0 on the Extreme, would the time capsule exhibit faster performance with downloading, streaming, etc?
  • Suppose I switch back to a Windows device in the future, will the Time Capsule still play nice? Would it be any different with the extreme and an HDD?
  • Are there any benefits for an Apple setup (Macbook, Apple TV, Airport, maybe iPhone, etc) to be working with a ime capsule as opposed to an external HDD plugged into an airport?

Thanks everyone.