Paper wasps are such bros! A month or two ago I stuck my hand into one of their nests inadvertantly, was greeted with what felt like electrical shocks, and my hand didn't swell or even hurt after a minute or two.

I will always come to paper wasps', or wasps in general, defense. I'm sure yellow jackets play an important ecological niche too, but I haven't run into 'em enough to have an opinion on their temperament.