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.
In South Africa doing lots of boat stuff. Departure north from Cape Town around December 15th. Arrival in the Caribbean around the beginning of February, after 5300 miles or so.