As title says, I made another guy (on horseback) and rendered his head in two ways.
The pathtracer is slightly better, most noticeable with the guy's left eye. Otherwise the differences are very small and only visible when you know they are there and you start looking for them. I wonder if this isn't easier and faster to get with curves in Photoshop. :)
Yes, you have to think whether to use PT over standard render or defer all. But I just rendered a part of a big render with PT where a wooden plank bridge was over ground, and the ground under it (and visible between the planks) was MUCH nicer. Shadows between grasses also way better. Too bad it still takes that long, but I guess there's no escaping that (yet).