I've found that all other brands have very weak Passion Fruit flavourings, this is the one that has the tang of the real thing. I wouldn't have any other brand of Passion Fruit in my flavour box.
It's darned strong though, I never go over 1% of this flavour in any recipe because it will dominate and can easily make things very bitter and tart (in a bad way!) particularly when paired with other citrus tropical fruits like Pineapple, Lemon, Lime and Orange.
It's useful when you want to add a more bitter tang to citrus recipes though, but that's not something I do, just mentioning it incase someone out there does.
I always mellow out recipes with this flavouring in it with Inawera Cactus and Capella Super Sweet at 1% each.