I haven't seen the blue in person, but I've seen the other one and it is a striking bag. It has a lot of extra details. The leather feels wonderful. I think the blue is more feminine but the black makes more of a statement.
Well I've been dying to see the orange and black one in person since the day I first saw it in the Fall preview thread way back in February so I couldn't possibly tell you which one until I've seen them both.
Like Brae^ I think I prefer the black/orange, but they are probably both stunning and different enough that you could keep both. What can I say? I'm an enabler.