I would say with the first two examples - the sawtooth and triangle - that the Prophet-6 was the first example and the Pro 2 the second. The differences were substantial.
In the third pair - the square - I would actually guess the second example was the P-6, which sounded better to my ear. But if the Pro 2 is the second of the pair, than I have to admit that it sounds quite good. The fourth pair - the PWM patches - sounds almost equal.
Paul, without giving away the instruments, was the P-6 sawtooth patch using slop, because the detuning was quite substantial? Is it possible on the P-6 to maintain a steady oscillator beating rate up and down the keyboard?