Some resources will still be exclusive to specific worlds, but not by real-world geographical location (i.e. Emeralds won’t just appear on Australian servers), this should give all players a better opportunity to find things they want without having to worry so much about how far away the servers are located.
It sounds like your ISP has fairly consistent routing to all the servers, which is why the AU servers is not better or worse than other locations.
Being near multiple portals will mean that more chunks across multiple worlds will be downloading and caching to your machine, which may be saturating your connection … you could try reducing your chunk download rate as suggested in this thread :-
This is basically due to the server not getting a response from the client (possibly for the above reason of a saturated line), so it is unable to update on the player position (the server needs to know your position as other players need to know that you’ve moved also). As the client has not received confirmation from the server that your last position has been saved, the client moves you back to the previous verified position, including the direction you were facing.
I hope I made that understandable … !
TL;DR
Try reducing your chunk download rate and see if that helps 