I was stung by one of these little guys about 11 years ago.
Unpleasant. And it hurt for several days.
Not that big a deal, though. Certainly not as painful as a hornet sting.
I got stung by one two weeks ago for the first time. While it was painful, it was the after effect that was the worst. Half my hand swelled up with intense itching that lasted for a week.
Another thing I didn't know, unlike yellow jackets and other stinging bees, they don't leave their stinger in your hand.
No hornet sting I ever got lasted for several days. Usually the pain is gone in an hour.