I've had this compressor for a couple of weeks now, and I luv it.
I play mostly metal nowadays, and have a very aggressive bass tone (with distortion), and the BC-1X enhances the pick attack and makes the tone more articulate, fatter and brighter.
I haven't dialed in one bad setting on it yet, which is pretty unusual for a compressor pedal. I think it's VERY easy to use.
I've tried it with great success on electric bass and double bass, with almost every setting possible.
It sounds good whether you squeeze the badjesus out of the pedal or use it it with lighter settings. I like to have a low threshold, a pretty heavy ratio, with a shorter release time on the compressor.
I believe it colours your tone quite a bit, but I like that sound, so it doesen't bother me, but that colouring is not for everybody. Although, at lighter settings I don't hear any colouring of the tone. The pedal doesen't generate any noise.
I can recommend reading Ovnilab's reviews on compressors before buying anything. He goes into detail in a nerdy and pedantic depth of many different compressors.
Could not recommend this pedal more! :D