Testing this morning on the way to work confirmed results in 45 degree ambient temps. I do have one small leaker left to nail down, but I'll have to pull the alternator to get to it. I'll seal it the same way I did the front one yesterday (no more teflon tape, I'm going with goop).
That'* a source of some of the small micro-bubbles also. I'm losing about a teaspoon an hour that is pooling on the flat part of the LIM above the water pump.
After I get that knocked out and all the bubbles burped, I expect another 5 degrees of efficiency across the board. Especially in a month or two when I ditch most of the antifreeze in favor of water wetter.
Overall, from where I am now, I expect to see 5-10 degrees more efficiency (20-25 cruising at low rpm'*, 30-35 during extended mid-boost runs, and 35-40 WOT sprints.