Iīm looking for a less noisy alternative to using servos for a project and I was thinking of using musclewires (Flexinol / nitinol wire) as an replacement. I havnt worked with musclewires before and wonder if this is possible or if they are very slow (I know they are driven by heat so slow cooling might be a problem)

Basically my project need to pull and push a small weight with a thin ironstick as arm. I need something that goes two ways. When I applies current to it I want it to pull and when I decrease the current again I want it to gradually go back depending on the current. Im using a pwm signal from my raspberry pi to control the current.

I wounder if anyone has some experience with doing the same? Basically replacing a servo with musclewire?

For example this one:
https://www.sparkfun.com/products/12096

I guess the thinner the wire the faster it reacts since it cools off faster?