(and glideslope is pitch, not power)
At the risk of starting another "Stick and Rudder" thread, I have to ask what you mean by "glideslope is pitch, not power"? Is this something peculiar to an Autopilot approach?
I'm not an IFR pilot but am fortunate to have a large under-utilised "international" airport in the vicinity who are open enough to have spam cans practising ILS approaches without the associated fees so have occasionally taken some foggles to practice an ILS approach - "just in case".
In my experience, it's exactly the opposite - glide slope is power, not pitch: I say this because I'll adjust the pitch (and trim) for my approach speed and then look to follow the glide slope using power..... I find if I'm too high on the slope and lower my pitch, I gain speed. If I'm low and increase my pitch, I lose speed.....