All subtractive synths have a lot of overlap--LPF, mostly the same oscillator waves, ADSRs that may or may not have additional stages, an LFO or more, etc. The main difference between the Rev2 and the OB-6 is the amount of modulation options you get--all of those LFOs, additional envelope, gated sequencer, mod matrix, etc. So there's a lot more available for sound design, evolving patches, etc. If you're more of a keys player that might be stuff you don't need and find that there's too much overlap to make it worth it. But for synthesists it's what makes the Rev2 so attractive--a genuine analog polysynth that gets as close to modular as anything else out there.