I don't have first hand experience with EVGA warranty service, but have seen they are good at standing behind their products. My opinion on extended warranties in general is that they are a big profit center for companies that offer them and therefore not a good deal from a consumer standpoint. I think with VGA's this even more so, given will you even want the card after the initial 3 year warranty expires?
You have a point, but equally if they did break, you could get it replaced with new then flog it....