General Rule of Thumb
This question has been discussed for nearly all sizes of boat, and the answer is the same: On the same boat, all other things being equal, you can sail closer to the wind and make better VMG with a fin keel than you can with a wing keel. If this is your primary concern, buy a boat with a fin keel. The question of off the wind is not so clear cut, and the results are more ambiguous between fin and wing keels. Some people believe that the wing keel is faster down wind than the fin keel boat is, while others don't think that there is much (if any) difference. A few years ago (around 1990), Beneteau did a study comparing fin keel to wing keel to scheel keel boats. As I remember, in all cases and points of sail, they reported that the fin keel was faster. *box Wing keels were believed by many sailors to be faster because Australia II won the Americas Cup due to their radical wing keel. In that case, this supposition was correct, but most people forget that this wing keel was simply a rule beater. The wing keel gave Australia II more keel depth when the boat was heeled than the standard keel for the American boat, thereby achieving greater stability than was possible without the wing. The place where the wing keel on Catalinas wins out over the fin keel (hands down) is in sailing or motoring in thin water. My fin keel C-320 draws 6.5 feet of warer, but the wing keel version draws about 4 feet. This difference in draft kept me out of a couple of marinas this past summer in Lake Michigan, and would make me think twice (or more) about sailing the North Channel with my present boat.
