STEC-30

I have the STEC30 in my C172, although no GPS steer since I doon't have
a GPS (that will be changing next month). As for the A/P I must say
that it is fabulous, imho. I don't have any experience with any other
A/P so I can't compare, but I can't imagine what more I could want
unless it was one with alt preselect and some o ther bells and
whistles. I figure I need to do some of the flying.
I don't understand the other writer's comment about the alt hold. Mine
holds flawlessly; no drift or variation at all, and it engages
immediately. Whether IFR or VFR, I would recommend it without
reservation. I also can't understand not having the alt hold; being
able to rely on the A/P to keep the alt lets me be comfortable while I
fold a map or reach in to the back seat without worrying that I'll
gradually and imperceptibly descend or bust an IFR altitude while my
attention is momentarily diverted. I agree that a perfectly trimmed
plane will theoretically fly nice and straight nut there always seems
to be something that changes what the trim should be as I fly along.
Also, a you know, the STEC is based on the electric turn coordinator,
so provides a huge safety cushion if (when) your vacuum system goes
haywire. How nice it is to know that the A/P will keep me straight and
level when the vacuum goes out!!