Let me just add,,,, the gsxrs have a more aggresive riding position. After riding my busa, and then hopping on my son's gsxr 600.. well, let's just say I don't think I could make a 2 hour trip on his. But I can ride the bus all day long.
I'm afraid if you get a gsxr.. you will get the wrong impression of the Busa. It's TONS more comfortable than them.