I think with the JW's, you are not going to get an accurate answer, because unlike some "religions", JW's have a private opinion and then their public one, and this goes for any issue. Take blood, almost all JW's will say they are against blood, but now many X-JW's will say that they never fully believed in the blood ban, they only went along with it because the Society said they had to. I think the 75% is somewhat accurate, and feel it is actually lower than that.
I do think that the JW religion will soften their stance on this issue alot quicker than the bible believing churches.