Part of the reason I've been using the power5x is because it's cheaper and according to people who didn't know which was which, they all thought power7x and 5x were the same, and thought they were both cleaner than vector; folks claimed the vector actually seemed to have a different and odd smell, not pleasant.
It's hard to say really that one butane from Korea is better than another butane from Korea, there are very few large exporters of butane in Korea (1 or 2), and they all produce roughly the same grade of butane lighter fluid. The largest factory in Korea produces 1 grade of butane gas, this is likely the same factory that produces vector, power, etc. True, this is mostly speculation, but what it all really tells me is: Closed System+N-Butane > Open System+Gas Solution in a canister.