If you place your orders for HK/Asia products to our US server, the first leg would be via commodity internet (which in your case would add about 350ms-180ms=170ms, then the order would travel inside IB's network back to our HK servers which would add roughly the same (I don't have any real numbers, so this is just a guesstimate). Thus you're looking at about 340ms additional delay if you were to place HK orders thru IB's US servers as opposed to placing them into IB's HK servers.