I am only basing my comments on my experience. As some folks will say, YMMV (Your Mileage May Vary).
I used SuperChips units on other vehicles in the past. I understand that the technology has changed and that the programming options or program functionality may have changed since then. Bottom line is I never really got much of any improvements except shift firmness. Oh, and I was remove the top speed limiter on the Yukon. The unit didn't have the tire size I needed to change to. And some folks have posted here that even the current S/C technology didn't get them much. I have no reason not to believe them.
As far as "learning" the PCM adaptives aren't removed or disabled as part of a aftermarket program load and new parameters have been installed, so the PCM will adapt to the new parameters.
In most cases, though, I noticed an immediate improvement.
As far as the bro-in-law's truck, adding an intake to get more air in would be strongly suggested. He is not getting the full benefit of the program because intake air is restricted.
The internal combustion engine is one big air pump. More air in + more air out = more power. The DSP programming will take advantage of the greater airflow.
Just my .02 ...