I recently tried "Vault" soda, and travelled back to the late 90's when "Surge" was the "in" drink... just my opinion, but it tastes just the same, only it's a Coke product not Pepsi
Vault is better tasting than Mountain Dew, imo. I usually drink Diet Pepsi but a bottle of Vault helps me through a busy day and workload. You drink a couple of them and you will have a decent caffeine buzz going without the heartburn Red bull gives.