I agree with what @sunbeast wrote, but I want to add that in my personal environment (passive basses with low'ish outputs, flatwound strings, soft touch, plucking between neck pickup and fingerboards), I chose the OC-2 for the reason that the tracking felt superb to every single analog octave I have tried.
I did not write that the tracking is better. It's just that it felt better. Other pedals would glitch here and there and give me a weird feeling, while the OC-2 instantly felt right and like my fingers could predict what I'm getting out ot it.
I tried a few clones and digital alternatives, and yeah, the VBO sounds so close to the OC-2 it really makes no difference, but with an unwieldy beast like an octave, especially if you're using the -1 with no clean signal, how well the tracking works with your style and gear is actually more important IMO.