As an American, I feel I have to say that Captain America could beat the crap out of Captain Britain, and then do a better job of policing the world.
Just kidding. I never liked the Captain America character, I always felt like his motto should have been "Remember kids: Never trust an immigrant." I can understand the need for the blatant propaganda when it came out, (40s) but you'd think that after the war they'd want to tone it down a bit.
I don't know, there is a lot to admire in the Captain America character. (I don't actually read his ongoing comic, but I buy the graphic novels because they are that good.) Outside of the X-books he is probably one of my favourite characters, and although I agree with you about his past, some of the more recent stories (over the last 15 years), have on occasion really taken a good grip and looked at just what all the symbolism means.
I'm not sure who would kick who in a straight fight between the two Cap's, Britain is certainly more powerful, but America is by far the better fighter... unless CB's sister joined in then CA is toast
Also, I don't understand why this was moved out of the graphic novels and comics section...