At the SSCA Gam in Annapolis last year they suggested a separate antenna as suggested here or a backstay one but with only insulator (at the top). I am replacing my standing rig in a few weeks and think I will go with the latter solution. The boat has the traditional rig with two insulators but these bits are quite expensive and if you don't need one of them ...
The rigger I am dealing with (Mack Sails in Florida) said he has never heard of an insulator failure.
Finished the circumnavigation in early February in Grenada. Have to work on a book project for the next several months so the boat will be waiting for next year.