Since it was an article about my dance series that started this conversation about role terms, I'll offer that the primary reason we chose "jets" and "rubies" as gender-free terms is so that regular contra dancers from other places can come in and dance without needing anything to be explained to them since the terms are pretty similar to "gents" and "ladies."  

We also took a look at this graphic of Ron Blechner's analysis of gender-free role terms people have been talking about: http://amherstcontra.org/ContraDanceRoleTerms.pdf

We may not use "jets" and "rubies" forever, but we figured we'd give it a try.  There didn't seem to be any reasons not to try and there are certainly plenty of reasons to try.  

Most men at our dance dance as jets and most women dance as rubies, but for the few who dance opposite, switch around, or whose gender expression doesn't fit the man/woman binary, I'd like to think that formally separating dance roles from gender is validating in a meaningful way.