I don't post here very often - as I am a multi-instrumentalist who plays mandolin, guitar and bass (both 'lectric and upright) as well as drums, but I find myself here more and more reading threads with interest.
I play a 2001 era Dlx American Jazz Bass into an Eden WTX-260 > Eden 210 XLT.
My rig is Boss OC-2 (Octave) > Vintage Mutron III > Ibanez Auto Filter > Subdecay Quazer Phaser > TC Electronics Chorus.Ring Mod.Flanger> Whammy IV> ZVex Jonny Octave > Carl Martin Compressor/Limiter.
I use the effects loop.
So in this rig I have 3 different octave options with the OC2, Whammy and Zvex (as well as 2 different Envelope Filters).
Typically the OC2 gets the dark, burnished lower octave tones that warm things up or make them evil. I use the Whammy either as an octave up or set to 5ths and this Jonny Octave is just an evil, freakin' ragged dirt creator with 2 setting, loud and lean trash or speaker cone shredding dirt.
All these options call for judicious and careful use of the octave effect because in the long run I strive as a bass player to not get lost in the toys, to remain musical, carry the bottom and the pocket and to support the singer.... but given the occasional solo break I'll carefully employ one or several of these devices layered together.
I'd recommend against the ZVex Jonny Octave - it sounds like a dirty and very powerful audible fart machine.
-Silvertone
SF, CA