I have the biggest size and it works beautifully with a full size package. It is almost weightless. The actual work is done by the filling. It absorbs vibration. The straps for an ad-hoc car mount are stored in the CineSaddle's pockets. This is more than an expensive pillow. The filling is like a bean bag refill, the outer material is indestructible and it has pouches for accessories. If you have the camera built so it doesn't sit evenly for low shots just place it on the CineSaddle. That's the lightest low hat ever. Maybe for a tiny camera the smaller versions work but I feel that choosing a bigger CineSadle will pack more filling under the camera, which will isolate it more successfully from any kind of vibration.
Say in a car, you can rest a camera built for shoulder mount on a CineSaddle that you hold on your lap and just hold it lightly to get rid of any jiggling action. You will still catch all the pot holes but the little vibration gets isolated really well. The less you have to stabilize in post, the better the image quality, right?
While I would love to see funds go to the original inventor (if it's a budget question) get yourself a Bean Bag refill on amazon or eBay and fill it in an old duffle bag. Play with that for a while before you commit to the CineSaddle. I am still a fan.