Now I can get back to trying to get a life!
In terms of sheer numbers, speakers of North American English far outnumber those of British English (and I'm talking only about proper "RP" British English, not the variations that are spoken around the world).
Learning one type over the other does not in any way imply the inferiority of the former (or latter)
Re: the "language and cultural idiosyncracies" bit could go either way too, not just for Americans.
Hmm... I'm not sure that Wikipedia should be claimed as the final authority on anything besides Buffy the Vampire Slayer and Pokemon
And methinks that Jimbo was being tongue in cheek. Any Brit knows that the Queen speaks weird English.