I am presuming that you are referring to either a PCB remote mounted antenna or the RPSMA directly on the module. The RPSMA allows for direct connection of a remote antenna that can have an increase in gain added. However, unlike the 900MHz band, the 2.4 GHz band has limitations on antenna gain vs required cable loss. In most cases, all you gain is the directional of the antenna and not so much of the gain.