Not sure how many people here play on multiple servers, but I wanted to make a thread to highlight major differences. These are all experiential, and by no means factual, but I have a lot of play on NA and EU (and enough on Asia) to make some broad sweeping generalizations. If anyone has anything to add, please do so!

I've found...
-Players on asia for arenas tend to prefer defensive cards. Antique healbot, fen creeper, and so on show up in a ton of decks. It's almost bizarre.
-In constructed, you see a lot more combo oriented decks, like inner fire and so forth.
-I also see more priest in both arena and constructed than EU or NA by a landslide. It's almost comical

-EU, on the other hand, is far more cancerous and aggro than NA. You see more face play
-For constructed, I label EU shamans as "aggressive flame tonguers", since they are far more likely to just drop one unprotected. This doesn't happen nearly to the same extent in NA
-Hunter is a far more popular arena class as well.

What's the point of playing multiple servers?

its fun

Europeans BM about 20x more often than Americans

I think the same applies for a courtesy well played at the end though

americans are used to winning