In 2017 there was $148,489,000,000 in remittances sent from the United States to other countries. In the list below you can see the top countries that received these payments. Ripple has taken steps to make big partnerships in majority of these top counties that are on the top of this list. Focusing on places that Americas already send money already.
Full chart and more information about remittance flows at https://www.pewresearch.org/global/interactives/remittance-flows-by-country/.
I have not been able to find enough information on what the process is for an institution that is currently using xCurrent and transitions to xRapix. I would like to imagine that it would almost be a seamless transition from one to the other. I personally sit back and see the progress that Ripple has made over the years and believe that all this was foreseen by them and was not only planned for but somewhat strategic.
In the video below Brad Garlinghouse Ripple CEO explains some of the differences between xCurrent and xRapid .