Technology
The only reason wire was used in rigging or sail handling was that it stretched less than the available line. Synthetic fiber technology has advanced to the point that wire now stretches more than "rope" of the same diameter. Wire breaks down to create "soldiers" that gash fingers, hands, and sails, so it is not a user-friendly material. The newest synthetic fibers are so strong that they offer less windage than wire does. Such thin line can create a probblem when you actually handle the line, however, because it cuts into your hands so easily. We replaced our wire/rope spinnaker halyards with all line about four years ago, reducing stretch and weight aloft at the same time. The major question we had was what size is most comfortable to handle, since the difference between 3/8 or 1/2 inch line is minimal as far as windage is concerned, and either one would handle our 1000 square foot spinnaker. Windage, with the halyards up against the mast, is minimal regardless. Besides cutting costs by not having to have a rope-wire splice, we save by simply tying our halyard shackles to the halyard instead of having them spliced. When the lines get worn, we can end-to-end them and get double the use from them-- something not possible with rope/wire halyards. Looks like a no-brainer to us. No wire soldiers cutting our hands, less weight aloft, less stretch, less (or the same) windage, and less cost. You decide.