They may be different, but I assumed the settings in the ai.cfg controlled the behaviour no matter what was used.
Other than some guesswork fumbling, based on the techniques described in the SDK, I would leave it to FSW to fix as well. I’ll bet they are using those default values though, just like the Twin Otter used to, and the Islander still does. Both of which had/have AP issues.
The last time I looked at this gave interesting results:
It was quite a simple test to do. While in the 172, on the slope, I was able to throttle up, and down, and the AP would maintain the slope quite easily.
Switching to the Islander, as I have said elsewhere pretty much since release, it was hopeless, and would either dive into the ground when reducing power, or climb until it stalled if you increased power.
The TO was similar in that regard. The AP just couldn’t compensate.