I have tried a number of bean bags..from the £9 cheapest to £40.A friend recommended this bag for use on a car door. Well,I just could not find a comfortable and effective position for my 500mm lens. I tried more filling..less filling but I always felt the lens was unstable. A good quality made product...it just didn't work for me!!
very nice little bag, don't do what i did and try to fill it with polystyrene balls, makes it nice and light however be prepared to cover the house in white snow as they seem to stick to your hands and everything else they come in contact with, should have used rice or bird seed (takes about 4 and a half kilos of rice) but makes it a little heavy to carry for any length of time. I would have prefered it to be just a little bigger.
Used this on safari in Kenya where it sat nicely on the open roof top :-) I haven't used all the extra strap bits and haven't taken it out for walks as it will be quite heavy when filled, but for the purpose of the purchase it was great!