They seem to fly more aggressively, but I really don't know if they're any worse any other bee.
I've been stung by yellow jackets on multiple occasions, always due to them landing on me and stinging me. They don't think twice about stinging, and their habit of landing on people, especially in the Autumn, when they're drunk, leads to a lot more stings than other wasps. I've heard they're a nightmare if you stumble on their nest, but luckily I've never had that experience. What makes them the worst is their sting. It hurts, and it can linger.
Native bees tend not to sting even if you touch them. They always fly away or to the next flower. They're too focused on that. Some don't even have stingers. I've interacted with thousands of native bees just over the past few years and have not once, to my knowledge, been stung. I say "to my knowledge" because many of their stings are no more painful than a mosquito bite, so if I've ever been stung, I sure didn't notice. Bumble bees are a little different because they're one of the few native bees that do live in colonies, so they'll protect it if there's a threat. I've heard their sting is painful.
