So I've been kinda waiting for it to heat up above freezing up here in Canada to do some actual testing. I started off in town cruising around the block at somewhere in the 93F area for the IAT's. After a few punches of the throttle I was able to get it down to somewhere in the 67F range. On the highway I got down to 63F. The base temperature outside was just shy of 74, meaning I was 11 degrees under ambient air temp on the highway under WOT (it will creep up under cruising conditions while it's not engaging)
I'm running a stage 2 controller which reads the TPS and works on a 5v reference. I haven't really tested to see whether or not I'm making additional power on a cooler day, but it most definitely restores power on a hotter day. It can drop 10 degrees nearly instantaneously with your foot into it. It's a progressive spray so it brings in more the more you beat on the car which is where you would normally start losing power from heat soak.