It is funny how all of you are simply ripping on one another instead of presenting generalizations about tactics used between Brits and Americans; or Shmuck vs shmuck for that matter.
Stay on Topic
On the topic of Tactics changing Internationally I can admit I have noticed several differences. In particular dealing with U.K players I notice that the more Elite the unit the better. American players, both in Warhammer 40k and any video game competition, prefer to have cheaper firepower, "en mass." This means they would rather stack up several squads of Heavy Weapons Teams for Imperial Guard instead of 1 Baneblade, they prefer Death Companies to Elite characters, and prefer to shoot you than CQB you. For the U.K part they will invest points in the more Elite unit because they tend to play much more conservatively, and will only commit their units when they see a advantage. U.K will favor Monoliths over Heavy Necron Warriors, Land Raiders over Cyclone teams, and SwarmLords over a horde of Warriors.
Another distinct difference, IMHO, is U.K players like to trudge it out, whereas Americans prefer to rush in. Many players in the U.S love Valkyries, JetFighters, and other Air units used to bring swift mobility to troop movements and deadly mobile firepower platforms to key positions. Many U.K players (especially at Pax East) have shown me they will stick it out with massive Artillery bombardments, Hordes of Elite Orks, or crush everything under the Nid Warriors claws. Slow and Steady vs Swift and Deadly.
As for other countries they have their own perks, particularly 3 Swedish players I had the privilige of facing at Pax East demonstrated how they love to use Elite special characters over basic Troops. I'm not even sure if it was legal for a 2,000pt battle with all the Space Marine character he had (High Marhsal, Castellan, Emporers Champion, Reclusiarch, and a Sword Brethern CS?? I was like WTF man???!!!). Funny thing was they both laughed at and abhorded me when I told them to use massive maounts of basic heavies for Imperial Guard. I still beat 2 of the 3. Anyway different places, different approaches to the same problem. Dog eat Dog world babe!!!