I've been using them for just over a year now and they have not failed me yet.
However, there was a time i ordered some "oils" from overseas for use in my soap. The first time it was fine, filled out the customs dec and package arrived safely.
However, when ordering anything with Alcohol (or flammable) they will force you to use a certain carrier only (I think it was USPS ). Needless to say it cost me more than the item I ordered, so I never used them for anything containing flammables ever again.
That being said, I have always found them to offer cheaper rates than getting AU shipping directly from who I am ordering from in the states.