Tried the following at one sitting, all at 80 proof, all unaged:
Old Gristmill Authentic American Corn Whiskey
(Shine on) Georgia Moon Corn Whiskey
Isaiah Morgan Rye Whiskey
The Gristmill is like an eau de vie; mild, a little sweet, a little flowery, no finish except a tingle on the tongue. I don't think I could have identified it blind as eau de vie de corn, but then corn is a pretty subtle flavor.
The Georgia Moon is quite similar, except that it has a little bit of funk that reminds me of a lot of Chinese white liquors. Less so, though; when friends and I tasted it against a collection of Chinese liquor, it was clearly the least funky. Maybe this is a taste of tails resulting from taking a fat cut in the distillation?
The Isaiah Morgan is also like an eau de vie, but spicier and more flavorful than the Gristmill. My son pegged the dominant flavor note: candy corn. Again, I couldn't really have named rye as the source.
I've had some Austrian "beer eau de vie", presumably a lot like unaged Irish whiskey, in the past; wish I had some to compare to these.