With a coin of this rarity, the particular certification company doesn't matter all that much (among the big 4) as the rarity will drive the price, not who certified it. So then the only thing the owner has to be concerned about is the longterm protection of the coin. With that in mind, many people think that the ICG does the best job of protecting coins from tarnishing, since they use the intercept shields in thier slabs. I'm not saying this is absolutly the reason he chose them, but it is something to consider...