Heat/humidity = lower boost, sadly
'Gator, you're not imagining things, AMHIK.
I recently brought my TT down here from Ohio (in August), and I was astonished at the seat of the pants difference. Previously, when I drove my car on cool Fall/Spring evenings, with dense cool air, the secondary turbo would explode into action, for lack of a better way of saying it. Upon arrival down here, with high heat and humidity, the transition from one to both turbos coming online is much more subdued.
However, now that we're into November, the humidity has dropped, and much of the same charactistics that I used to realize have returned. I'm not too worried about the performance output based upon the climate around here however, after all, it's a kick to be driving the car with the targa removed in November ;-)
I wonder if a large FMIC, even with stock twins, wouldn't be a good idea here in this part of the country.