I agree with this (from Saveur)
If there’s one thing wrong with most American treatments of Thai food, it’s how its famously hot, salty, sour, and bitter flavors all get toned down in favor of sweet. Pad Thai should not taste like it was made with ketchup, and a proper som tum should be more about lime juice and chile than sugar.
Sutta’s SD Spicy Sauce is the solution. Hmmm … on my next trip across the pond, I must find some to bring home.