To me, RedBull Sugar Free tastes a lot better than any other sugarfree energy drink out there. Even though the size (8.3oz/12oz) is smaller than other brands (i.e. Monster 12oz/16oz), the effect lasts just as long.
I gave it 4 stars because it is still expensive, even more so if bought in bulk.
My advice; Save your $$$, drink CocaCola. Or if you want to taste the Taurine, go with Monster or Rockstar or Full Throttle, and get 16 oz for less than the price of RedBull.