Been running the plugs about 12 days now and other than a few more misfire-feeling things on cold startup, they're working just fine. I was still getting some negative corrections when it was crazy hot (over 100 F), but after chatting with TurboGT a little bit on it we have concluded the negatives are likely just a product of the lousy "91" octane I'm dealing with here. Thus, I've been putting a gallon of E85 in the car with each fill-up, and it's knocked down the negative corrections to basically 0. I'll still get a little blip on take-off sometimes, but that's expected.
The car definitely runs fine with the Brisk plugs... Had to get on it this morning to squeeze into a space between a truck coming slowly up on my left and the guy in front of me, and after dropping it into 4th at 73 mph, it scooted right up past 90 pretty quick. 25.6 psi and 0 negative corrections, and that wasn't even WOT.