Some time ago I fussed with this type of stabilizer for quite a while:
My camera is a GH1 but I think the characteristics of this type of stabilizer are pretty much the same for any camera. Overall here's what I found out:
1. Balancing the camera on the stabilizer is a bit tedious but can be done OK. However, once done ANY change to the camera that affects its center of gravity (CG) throws the balance off. For instance, changing the zoom value or re-positioning the camera's strap will throw the balance off.
2. You have to walk/move very carefully because the stabilizer does not smooth out vertical movements.
3. Depending in the amount fo friction in the stabilizer gimbal it may be either too easy or too difficult to turn the camera side-to-side. If too easy you get unwanted turning; if too difficult you have to twist your body.
4. Holding the camera & stabilizer in a good shooting position gets tiring pretty quickly. Changing hands adds unwanted bounces/shakes.
5. Packing the stabilizer in a suitcase is a bit awkward and you will get stopped at the security checkpoint if you do carry-on.
Bottom line: there's a reason the professional Stadicam rigs cost $3000 (or whatever they cost.)