I bought the CHAdeMO adapter for peace of mind. We drive up to Breckenridge to ski fairly often. There is no Supercharger between here and there, but there is a CHAdeMO charger. To use the supercharger I would have to drive out of my way like 40 minutes (round trip). I haven't needed to use the CHAdeMO adapter yet because my MS can get me there and back without a charge if I don't drive around too much, and because there are Level 2 chargers in Breckenridge that I can use.
But, even though I haven't used it (other than to test it), it has made me braver with respect to not bothering to charge in town. I know that I have the option to get a relatively fast charge on the way home if I need it, so I don't stress about topping off the battery as much as I used to.
I consider it money well spent.