fatboy on the way

My first fatboy is in transit.
I have been using a Merkur HD for 2 years.
Any tips?
I know the settings are 1-9.
Which settings are more aggressive?

higher numbers are more aggressive.
The wiki has a blade gap comparison chart for gillette adjustables vs. merkurs.

9 is most aggressive, with 1 being the least. There is a chart in the WIKI that ranks razors by aggressiveness HERE