I spent some time trying to figure out if the P6 with 6 voices, 1 LFO and not the largest set of modulation would be justify the expensive price, considering a Rev-2 16 Voice is considerably less, with considerably more features.
But, the P6 sounds absolutely wicked, the price is completely justified. Despite the relatively simple modulation options, this synth pulls of the most amazing, deep and rich sounds.
There are many "sweet spots" that can be found in a short amount of time, making for a very immediate experience.
Its just such a great synthesizer. Do yourself a favour and get it. Do it once, do it right.
Tip: The default patch set is not the most inspiring, so I encourage new users to search out and find better ones.