I'm not saying you'd be able to distinguish one brand from another necessarily, just that low quality vodkas have characteristics that make them decidedly less pleasant than others. Unnecessary burn at the back of your throat, and a weird rubbery aftertaste.
Just a note, I'm not correlating price to quality all the time. Wyborowa for example is less than $30. But you can definitely tell this $17 bottle of highwood vodka is a $17 bottle of vodka lol.
Edit: this is a decent short article on it. http://www.theglobeandmail.com/life/food-and-wine/wine/if-vodka-is-just-ethanol-is-it-essentially-all-the-same-from-brand-to-brand/article22178962/
The differences in flavour are due to the quality of the raw materials and the distilling process...