I bought one for $5.49.
The bun was a bright red that reminded me of a mushroom in Super Mario. Inside, the crumb was almost neon red. In texture, it seemed softer and moister at the surface than the standard Whopper bun. There's a definite heat to it but no added flavor otherwise.
The pickled jalapenos similarly packed a solid kick along with a sharp sour bite.
The lettuce quality was marginal with mostly wilted leaves that offered little in the way of crispness. The tomato fared a little better but wasn't great either. The jalapenos actually offered the most watery crispness here (at least on this occasion).
The bacon was very nicely crispy but was light on smoke and flavor.
Nutritional Info - Burger King Angriest Whopper (315g)
Calories - 830 (from Fat - 460)
Fat - 51g (Saturated Fat - 17g)
Sodium - 1530mg
Carbs - 59g (Sugar - 17g)
Protein - 34g