Throttle = Height, Stick = Speed is what I've been taught and use in the PA28. Always and never, ever, anything different.
Aiming for 70kts on the final approach, everything lined up for a greaser of a landing and it is fine. But things don't always go to plan so I pitch down to maintain the speed, keeping to 70kts (slowing down is much easier ;-))
Sometimes though this might bring you a little low on the approach so power is needed to get some height.
Once you start to do the two together quite smoothly it can appear that in order to maintain 70kts you are applying power, but in reality you are pitching down, gaining speed, losing height, applying power, gaining height - maintaining the right approach.
Does that make sense?