Electro Harmonix Bass Preacher

I bought this stomp box because I wanted to add some extra sustain to mij bass sound. After all the product is called a compressor/sustainer. However, I can really find no difference in sustain, with or without the device on. And the compression? Maybe a little. But I must say that up to now I have only tested the device in a home situation. Maybe it depends on the type of amplifier one uses, and maybe on stage it will perform better, although my experience is, that at the stage it is often the opposite, so that I often decide not to use a certain stompbox.