Or is it like a triple distilled vodka-a neutral spirit with no or little flavor? I was given a bottle of Hudson Valley white corn whiskey-and if it has no flavor, I think I’ll just keep it unopened.
No, it has flavor. There’s a corniness under the alcohol burn. I just find that it’s rather one note. Corn whiskey needs a lot of oak to develop those wonderful bourbon flavors.
What’s it good to mix with?
NASCAR and dating your cousin. 
I’ve only had corn whiskey once: at Makers Mark distillery, the tasting had “white dog” (unaged whiskey) as part of the line-up. It was interesting, to me, at any rate. It tasted to me a bit like a cross between tequila and a fruit brandy like slivovitz. Definitely did not taste flavorless or anything like vodka. I actually quite liked it, but I like rough-around-the-edge liquors a lot, so I wouldn’t expect most people to enjoy it. I bought a bottle of Makers White and it was gone within a couple of weeks (so, technically, I guess I’ve had it more than once, but it was only that particular brand.)
Everything has a taste. I’ve mentioned before on this board that my (now ex-) wife and I were well on the way to opening a distillery in 2007, before the economy tanked and investment dried up.
We attended a distilling conference at Cornell’s Vinification and Brewing Lab, sponsored by Christian Carl. It was a small and informal affair, as artisan distilling was just beginning to take off in the U.S. (about 20 people attended, and the U.S. rep and German VP met us at a hotel bar to discuss plant plans, to give you some idea of the scale).
‘We’ distilled some few gallons of applejack that day (picture me standing about where the foreground vat in the first link is). We ran out of that pretty quick, so the organizers looked around for something else. We looked around the lab and found (wine lovers should not click this spoiler)…
a thousand gallons of port
that we proceeded to turn into first run vodka.
The next day we went to Montezuma Winery (equipped by Christian Carl) which had just set up its first still. And we ruined a few thousand gallons of mead. I could still taste the honey…
TL;DR
Vodka is not ‘neutral’. I know that vodka made from applejack tastes different than vodka made from port tastes different than vodka made from mead.
Corn whiskey isn’t strictly speaking the same thing as White Dog straight off the Bourbon still, but it is close.
It tastes sort of corny, in the same way that say… white rum tastes like molasses. Subtle, but there.
If you want an interesting corn whiskey, there’s a Texas distillery that makes a toasted blue corn whiskey. It tastes, I shit you not, like tortilla chip liquor.