Regarding grainy renders and long render times:

If you have P12, make use of Adaptive Sampling w/Threshold. When engaged, Superfly will note when a given pixel no longer changes with continued samples (i.e., "this pixel has already reached Nirvana"), and skips that pixel thereafter, devoting its time to more difficult areas of the render.

With high quality settings, you'll see slow progress at the beginning of the render (same speed as P11), but at some stage the progress will begin to accelerate, and as more pixels are finalized, the render progresses very rapidly. For me, this feature alone made P12 worth it.

I have 2008 vintage equipment, and my video card is not good for GPU renders, so I'm limited to CPU-only renders. Take a look at these P12 Superfly renders which have a lot of metals, volumetric water, meshlighting, etc. No grain remaining, but they did take over an hour to render on my workstation.

undersea ruins

Appleseed Jedi

Cortana and Master Chief

Elven Grey Ship

These are the render settings I used for the Grey Havens renders; zero out the volumetric values if your scene doesn't have volumetric materials in it.

Poser 12, in feet.  

OSes:  Win7Prox64, Win7Ultx64

Silo Pro 2.5.6 64bit, Vue Infinite 2014.7, Genetica 4.0 Studio, UV Mapper Pro, UV Layout Pro, PhotoImpact X3, GIF Animator 5