I have made it to one UK Scale Model World back in 2014, and about a half dozen US Nationals. The difference between the two that was most apparent was that in the UK the non-competition club displays outnumbered the contest entries by a considerable margin. The vendor rooms were stupendously huge with more stuff than I could mentally process. I felt the contest entries, although fewer in number compared to a typical US Nats turnout, were of generally higher caliber in quality. That's not to disrespect the US Nats, it just seemed that the heavy hitter modelers were the ones to enter the contest. A friend who I regard as an expert modeler only managed an "honorable mention" for his entry. I didn't bring a model to the contest, but if I ever do, it had better be pretty darn impressive!
It may be far away, but guys in the US should go at least once to Telford, just to experience it and see how they do it "over the pond". Plus there's the RAF Museum in Cosford a couple of train stops from Telford. Heck I'm in the middle of the Pacific Ocean, and it was a lo-ng flight. But I watched six movies so it wasn't too bad!