I just read about this mod to the ACC system on Foresters that is alledged to greatly improve its performance, by improving airflow across the sensor that measures cabin temperature.
Those who have installed it say it reduces the tendency of the system to overcompensate heat- too hot, then too cold, then back to too hot, etc. Aside from the non-intuitive interface issues, I have noticed that the system does have a hard time maintaining an even temperature.
I would be very curious to know if the mod is as straightforward to install in an Outback or Legacy as it is in a Forester:
http://www.geocities.com/samiam_68/SubaruCCS/SSC_Fix.htm