While the Pro 3 can certainly act like a chameleon and is able to cover many sonic territories, two things stood out for me while getting to know it during the sound design stage: One is the already mentioned abrasive quality, the second one its pleasant analog character. Not only the return of the Grunge parameter made me think of the Evolver quite often. The Pro 3 is certainly capable of creating the sort of aggressive sounds that lend themselves well to genres like industrial, just like the Evolver. Albeit I'd never say that they sound the same, they certainly share a unique sonic identity in that direction. Of course the major difference lies in the signal path: The Evolver offers a stereo signal path from the frontend to the outputs while the Pro 3 is mostly a mono instrument in that regard (minus the stereo effects and the stereo output signal).
While the full stereo signal path is an ingredient that makes particularly the Evolver's analog side sound more dynamic and alive compared to identical sounds created on a Prophet '08 or Rev2, the Pro 3 provides the breathing quality of analog sounds even without the extension of a full stereo signal path. To me it felt like the VCOs were loosened a bit, maybe just like it was done on the OB-6. I can't verify whether this is what actually happened, but I never really felt the urge to make much use of the slop parameter if I wasn’t going for something like lo-fi sounds. There always seemed to be enough movement between the analog oscillators by default or at very low slop settings.
Although two of the three really musical analog filters of the Pro 3 are similar to the Pro 2’s filters, the Pro 3’s overall sonic character differs quite a lot from the Pro 2. Both might share quite a lot of similar features when it comes to elements like the sequencer, for example. But when it comes to the core sound I’d describe the Pro 2 as more polite than the Pro 3. Adding sound design tools like the Pro 2’s linear FM capabilities to the equation, I would also say that the Pro 3 can’t replace the Pro 2 and vice versa. The similarities aside both synths share on their front panels, they are actually quite different beasts sonically. So much so that it makes perfect sense to use both for the sake of variety.