Well, I'm posting the result in the gallery now, it's called Clear waters.

I'm not sure this was the best test , since I have a proc terrain, an ecosystem, water, soft shadows and GI;, rendered at 1800x2400, and it took 24h to render without AA.

I must say that the result is absolutely convincing, and my soft shadows are not noisy.

Now I wonder what would've been the render time with my usual AA settings, but at 800x1200.

Guess this is time for another test!