Remember folks, when operating within the cooling limits of the Rad, the thermostat dominates. You might still see a degree or 2 difference, but where you notice the difference is when the Stat is Wide Open and the temp starts creeping above 190-200F. If you are above the heat shedding capacity of the rad a cooler thermostat does nothing(or very little).
I agree with mwhenes about pulling the laminova. Not that there isn't a place for that, but when you want to double or more the whp output and run it on the track(sustained load), adding more heat load to the existing coolant system is counter-productive. Better to run a separate side cooler for the oil.
The reason the F1 is so effective is that it has very tight tube and fin spacing. The tubes are 1/4" on center, I believe. Thus the surface area is very high. Thinner helps because as you increase the surface area you naturally restrict flow of air. Since has far less heat capacity vs water, the temp of the air as it goes through the rad is already quite high as it passes the first 37mm, there is little point to going thicker. It just adds airflow restriction with minimum cooling. The theoretically perfect radiator has the perfect balance between maximum surface area(restriction) and thickness. We've approached this the closest with the F1 rad. It supported our 380WHP Optima car very well. For most users the 42mm all-aluminum rad is a great improvement in performance vs cost.