- How deep/complex is the P08 compared to the P12? Can the P08 do things that the Tetra can't, or is it strictly an 8 voice version of the Tetra? How easy is it to program modulation/sequences? That was the main thing that I found tedious on the Tetra.
The Prophet 12 is much deeper than the Prophet '08, but the P'08 is not a shallow synthesizer. The P'08 is excellent at designing precise musical sounds in the old school/vintage tradition, and yet its modulation abilities go well beyond it. It can do most everything the Tetr4 can do, minus the distortion. It's larger size means that the layer and split modes can produce more flexible and fuller sounds. But its tone is undeniably Tetr4-ish. I seldom use the sequencer, except for controlling modulation - usually keyboard triggered. I do find it quite easy to program, though.
The issue between the P12 and the P'08 comes down to your individual needs. There's no doubt that the P12 is a monster of an instrument with almost unheard-of capabilities for a non-modular keyboard synthesizer. If you want a vast array of sonic capabilities, if you'd like to design deep and complex patches and noises with precision, then this is the instrument for you. But the general consensus is that, although it can do old school/vintage type sounds, these are not its strength. There's much debate over this, but most agree that it's good at old school/vintage type sounds, but not great. Based on my research of this instrument since its release, I would definitely agree. And I think it's safe to say that it's not a substitute for the P'08. The P'08 shines at a wide range of old school/vintage sounds - organ, brass, strings, pads, sawtooth and square leads, and much more. And because of its nearly parameter-per-function control panel, it's much easier to use than the Tetr4.
So, the key is in your own needs. Both instruments are superb in their respective corners, but one cannot replace the other.