Nice write up, your experience tallies with my own.
When I AB'd them, I was using a Japanese "Octaver" pedal, and the results were mostly the same. In headphones, I did hear a slight tonal difference between the two, but never anything anyone would pick up on without them being side by side, and certainly not through a loudspeaker/in a mix.
Anyone using an OC-2 because it sounds better is kidding themselves. Don't get me wrong, using an old Japanese OC-2 is definitely cooler (I bought another one after I sold the OC-5 years ago!), but that's all it is.