Right now FNAWS is offering a chance at a Fannin Sheep hunt if you join, so now is a good time for a chance at a hunt.
I have not heard the results, but GSC/OVIS was sueing FNAWS for using the Grand Slam "Intellectual Properties", etc. It appears to me that there has been some turf battles between the two groups for some time. I used to be a member of both, but after the law suit I dropped out of GSC/OVIS because it felt like I was supporting a law suit against myself.
My feelings are FNAWS puts more effort into putting sheep on the mountain and that is why I support such organizations. GSC/OVIS admits that they are more of a record keeping organization, although they both try to help the cause for sheep hunters. So, for what it is worth, if you have to make a choice, I would join FNAWS