There is a Vodka called Tanqueray Sterling that is out, it is very clean and nice. Grey Goose has a slight berry flavor to it. You can only taste it if you try another vodka first, then the Goose. The Tanqueray is very good, without the slight berry taste.
The reason for buying more expensive vodkas, is the process they go through, the number of distillations, and filtering processes. The more processes, the more impurities will be removed. This will keep you from tasting lousy vodka, or getting a headache. (unless you drink WAY too much) ( I have been guilty of this before..)
I have tried every Vodka on the Planet. In 2001, I was the distiller at Tito's when they won the Double Gold. Tito and I used to buy and taste all the vodkas we considered competition, then, I would stay up all night with the stills to make sure the product was perfect, while Tito chased his ex, Tasha, and his present wife, Lori. (and others)lol....
Anyway, you are right about Tito's. He sold over 150k cases last year, and made a profit of over $5 million. His production has increased, and the quality has decreased. I suspect his life is still pretty good.