It depends on the
wind angle and
wind strength (and on the cut of the sail, of course).
I have a Code 0, an A3 (an
asymmetric for beam reaching), and an A2 (an
asymmetric for broad reaching and downwind). The Code 0 is on a top-down
furler, the A2 and A3 are on a sock.
The sail that gets used the least is by far the Code 0 for three reasons:
- Beam reach: the wind angles/strengths when it is better than the A3 are not that many. Basically, anything greater or equal to 90 degrees, A3 is way better. Between 70 and 90 degrees, Code 0 is better. Below 70, Code 0 starts to be tricky, it is probably time to use the
jib.
- Broad reach/downwind: Code 0 is not cut for downwind. A2 of course is ideal, you can stretch the use of the A3 to broad reaching in > 10 knots by easing the tack line; nothing you can do with the Code 0.
- Top-down furling conceptually sounds like an easier sail, but in practice the sock is so much more reliable and fool proof, especially in > 15 knots.
In percentages, roughly, the A2 gets used 65% of the time, the A3 25%, and the Code 0 10% of the time or less.
If I had to only pick one sail out of the three, I would pick the A2, it is by far the most versatile sail (you can fly it even at 90-100 degree angles, although of course not ideal, and it blows the other two
sails by a lot for 110 degree angles and above).