It's post turbo, just at the bend of the exhaust elbow coming out of the turbo.
It appears that the truck I bought has the Banks Stinger-Plus system, which includes the entire exhaust system that reduces back pressure, as well as the turbo mods and waste gate system improvements. I think they have a lot to do with the low temps...not to mention that the pyro sensor is downstream (about 2") of the turbo housing itself.
I'm thinking about adding the Banks intercooler, since mine's stock. I want to find out if it's worth the cash.