Hi, I'm new to the forum, but I have a lot of experience with both Smaart v7 & 8 and SysTune Pro.
What you're describing in SysTune, is in Spectrum, you can choose either "Full" or 1/1 thru 1/96 octave banding. What "Full" means, in this context is, the "full" FFT (raw, unbanded FFT data).
This means that you are choosing to view the full unbanded FFT, and as such, viewing pink noise on such a display will show it having downward tilt from left to right, as a result of pink noise being equal energy per OCTAVE, not equal energy per FREQUENCY. Since you have chosen, by selecting "Full", to NOT apply octave banding to the data, an acoustic measurement taken in the traditional way, using pink noise, will show a spectral tilt that is lower on the high end and higher on the low end than a conventional fractional octave banded measurement.(like an RTA) This would be the same thing as choosing "Log" in Smaart when in RTA mode.
A more "conventional" RTA style measurement can be accomplished in SysTune by instead choosing one of the fractional octave bandings 1/1 thru 1/96. Alas, this is but one way to see the incoming data on your measurement channel in SysTune. The real power of the program, in my opinion, is it's awesomely stable (when using periodic noise) Transfer Function measurements and the ability to overlay IRs. Virtual EQ and Delay Analysis are also awesome tools that have taught me a lot in the last couple years.