the only advantage I could see (someone with more knowledge over the JK can speak up) might be better quality suspension components ( I thought the rubi and sahara came with gas shocks for example. the electronic disconnects may also be an upgrade over your model. I still would not spend any money to purchase a used rubi stock suspension unless there where significantly better quality of parts or to replace damaged/warn parts on the stock unit.
I was sure the rubi came with bigger tires as well, so there may be some lift over stock, but I doubt it would be anything substantial.