The 3100 uses a much different HP profiling set up than does the 3200.
APS on the 3100 does indeed use a hybrid PM app but is different in that it uses a version 6 library for creating the profiles.
APS for the 3200 uses Monaco libraries which are , I assume, from Profiler Gold but modified of course for APS and the ESP.
The HP Color Center Profiles on the 3200 are really greatly improved over the 3100. I saw some areas that were better with APS but nothing saying that they were not at a pro level where as the 3100 are not as well tuned for photography outside of matte paper.
The integration with the ESP and APS is ideal. I cannot say it will give you better results over a Spectroscan but will say it is very easy to keep consistent prints and measurement values onboard without extra time to set up the spectroscan.
I have an i1 and PM5, and a ColorMunki but don't use them for the 3200 profiling as it has APS. The Color Center profiles are in all the tests I have done on a high level as well, so I see no reason to profile outside of the printer.
A. Diallo wrote recently on how to use charts with more patches with APS where you could use the 1728 patch chart or more if you think you gain precision.