Basically, the Asia region is a server you'd NEVER EVER want to be in. Seriously, 1 hour queue for log-in, jam packed with people.
I've never played in the Asia region but that's what people say when they tried the Asian server.

Just play in the US region, lower latency. Plus, you won't have to deal with all the gold farmers from China. They'll destroy the AH.

The SEA version of the game, by default redirects you to the US region. There's no difference really compared to the US one.

As for the updates, obviously the US region gets them first 
But I think all servers will get updates at the same time.