Vodka's job is to add warmth to the drink. It really isn't supposed to have much of a "taste" at all. Tito's has always been really good at just getting out of the way.
Hennessy cognac is something I like to use to demonstrate glassware and environment. That is, if you pour Hennessy into a shot glass and swallow it, it hurts! It's a cold bite of ethyl alcohol that just really isn't that pleasant!
If you put that same shot into a snifter and let your hand warm it for about 5 minutes, then sip, you get all the happy esters in your nose from the bulb glass. The warm liquid becomes almost candy type smooth with none of the brutal bite the shot had.
It's also why it's a crime to drink it outta the bottle! If you're just looking to consume booze, by all means be my guest! I do it too on occasion. Just don't waste the fine craft built into the cognac to do it.