I have a Chinese one in metallic red lying around somewhere. I've used it on the Epson R-D1 in the past, but that didn't seem to work very well. So the thing has been collecting dust over the last 3 years.
If you are using a soft release, you must be careful with it. If the SR is mounted on your shutter release button, protect it from impact. I talked with Sherry Krauter about soft releases; she said that she had to repair a couple of film M cameras that had been dropped on their soft releases; the internal damage to the camera was astounding.
Soft releases are a nice accessory to have and they do help. Just be sure to exercise caution.