I had my new Evo 70L out on an EPIC day at the Hatchery recently (7/6). I was overpowered on my 3.2m sail and the swells were nearly mast high at times. The board was a treat in these fierce conditions!
I tried the stock Drake fin and also a True Ames Enduro 20cm. I found that the Enduro (which is stiffer than the stock fin, but similar surface area) had more grip in the chop and "bit" better when landing jumps. In all, I think I like the Enduro better - makes the back end of the board a bit "firmer", but still keeps that groovy Evo skatiness.