I have the z-fin 38cm that I use with my 7.0. I also have a MFC 42 that I use with my 8.2.
The 38 is very good with the 7.0. I am thinking about getting more z-fins as I believe it is not just the size of the z-fin that makes it feel good, but the fin. Reason for my question is that I am not sure which size to get next. How big is a difference?
I know Taty Frans says the 40 cm is the best for the 2013 110. I am the same weight as him, but I am not sure I sail with the same omit of power.