Back in the 90's, the UK Predators came close to winning it.
Since then, Pete Robinson - who owns this forum - has played for two very successful US teams, Aftershock & All Americans. He won a number of titles with them, and has even won the "Top Gun" title - which was a 1 v 1 event.
A number of UK teams have since played the World Cup with varying degrees of success. Shockwave, Nexus & Tigers, as Liam says, are a few. A group of old friends known as the "Sandbaggers" also make the trip each year.
World Cup used to be held at a woodland site, but as the game has evolved it moved to Disney's Wide World of Sports at Disneyworld, Florida.
It's now held at "Fantasy of Flight" in Florida.
Going to World Cup is a great experience, and to some players, it's their dream. See if you can arrange a holiday in Florida at the same time its on, and you can sample it yourself.
In 1993, I arranged my wedding & honeymoon so that it took place at the same time as the Nashville Masters, which was a big event back then. Since then, I have been to a number of World Cups - they are held in October, so flights are a little cheaper then.