Colin, Jerrod,
Thank you both for your points.
My issue is actually that Visual RF is understating the 225's coverage:
(I manually drew the Aircheck map to illustrate the readings we were getting... basically green = -65 dBM or better)
The difference between the two is large enough that VRF estimates are almost of no use.
Seems like there would be a way to "calibrate" VRF somehow... dunno, just throwing out ideas...