I've been looking at Octave pedals but haven't had the chance to try many out...I'm particularly interested in the EBS Octa-Bass...has anyone here had any experience with it and if so what are your impressions. How well does it track down on the E string (on bass)?

I would personally get a whammy pedal- good
octave doubling with other effects for cheap

You're going to be hard pressed to find an octave pedal that tracks down that low. I own and EBS Octabass and I have tracked it down an A (on the 1st string, not an open second string). Every now and then, I can even get by with playing cords. I owned a Boss OC-2 before I got the Octabass, and there is really no comparison, the Octabass is by far the better pedal. Plop down the extra money for the Octabass, you won't be sorry.