If anything, I would run the more advanced setting. 16 degrees should be fine. The timing specs from the source country may be different based on differences in fuel. Like the UK could run a little more advanced timing since their fuel is higher quality (95 and 97 octane on up). If you are running premium, which I hope we all are, the more advanced settings will usually be beneficial (don't go to far, ie. more than 20 degrees, it won't help).

Just remember that stock settings are not there for max performance, just for reliability. They are safe for stupid drivers that put lower grade fuel, and safe in case you get a bad batch of gas. If you run premium or octane boosters, you'll be fine.

Jung