I finished up the right speaker tonight and connected it to one side of my F5 and left the Cornwall on the other. Due to the different sensitivity (100 vs 90) I had to set the balance leaning towards Big Bob, but otherwise they are on an equal.
Oh dear, it's a good thing I need the Cornwalls for my SET amp or I'd be listing them.
Big Bob is more detailed, the Hiquphon tweeter is much clearer than the CT125 of the Cornwalls. I'm also not lacking in the bass end either. Overall a cleaner, more responsive speaker.