The stabilize filter works very well in my experience.
Here’s an original shot:
And here I applied the stabilizer with a full setting of 10 shakiness and 15 accuracy:
However, if the shakiness of the original is too much and your settings are too high, then you might end up with something like this:
It’s best to experiment with each individual shot. I think the default settings would work OK in most cases.
Also, I sussed out the zoom setting: the filter is clever, and zooms in the shot to cover up the untidy edges where the frames are rotated to compensate for the shakiness. Cool! Also cool is the fat that you can adjust the zoom after the stabilize filter has done its analysing and see the effect in real time in the preview screen.
The smoothing feature allows you to add a touch of blur to make the processed shot, er, smoother…