First let me say that i am no vodka expert but i have tasted ( i stress tasted ) a large variety of brands, in different quality ranges. I enjoy mixing and creating martinis, some individuals have even made a variation of my name in association with martinis. With this being said, i offer my humble option that Kirkland Signature Vodka from Costco is a liquor of high flavor and quality, it has a very clean taste with no after bite. I would even go as far as compare it to Grey Goose vodka.
This is where the vodka and Internet communicate come in, some are unsure of the spirits origin, few believe it is Grey Goose in Costco guise. Finer vodkas have a lighter, crisp flavor depending on the number in the distillation process. The Kirkland vodka i believe is distilled more than 4 or 5 times giving it its smell and savor of value. Costco's warehouse offered price of 29.99 for a 1.75 liter bottle adds to the worth of this drink, most other vodkas can easily go over this cost for the same quantity but not have its level of caliber. It is definitely worth a try and you will not be disappointed, the bottle is very elegant as well.