My son was stung but it wasn't even nearly as bad as a bee sting. I'm glad I didn't destroy their nest now in light of your info. The gear; Nikon D80 with an 18-105mm Nikkor, 67mm diameter.
If they are the ones that build an umbrella shaped nest rather than the long chain type nest (and they look like it) be very careful. They can be very territorial and the first thing they go for are the eyes.
You all have me confused now. They DO have an umberella nest. My son WAS stung. It did NOT hurt at the time of the bite or any time afterwards. They are defensive of their nest and certainly faced me and warned me off when I shoved 67mm of Skylight filter in their face. A few (never all) faced me and began buzzing their wings, which is why you can see the wings of the "egg tenders" but not of the 2nd guy who was trying to stare me down. I am quite colour blind and I have used the "vivid" option in my D80 to punch the colour up in these shots; but I was most surprised to see just how colourful these little critters are. Before photographing them they were just grey insects that floated round my barbie area. I studied these guys for some months; until they deserted the nest. Here's a fuller piccie of the nest which I initially excluded because the extremely shallow depth of field meant that I could not get complete focus.
If his sting didn't hurt he was lucky. Like a snake, wasps can sting but don't always deliver a venom dose. It maybe they are a different species to the ones up here but they look very similar.
I have worked in the landscape, gardening and horticulture industry for years and have been stung numerous times. They are one of the few insects that really put the willies up me when i see them. The most memorable was being stung between the eyes just above the bridge of my nose. Luckily I had sunnies on. I thought someone had hit me between the eyes with a hammer.