With 5.7 release, "Frequency scaling has been moved from apmd(8) to the kernel with an improved algorithm." :
http://marc.info/?l=openbsd-misc&m=143043178115828&w=2
http://cvsweb.openbsd.org/cgi-bin/cv...75&r2=1.65&f=h
It is very reactive now, and "-C" is not an option anymore.
So as a conclusion of this thread apm -A won!