Quote - Displacement mapping is ideal, but most people who create textures here seem to only create bump maps and and treat them as displacement maps using the displacement node. That's not really using displacement mapping, and won't enable you to add the sort of detail you can attain using Z-brush on lower poly proxies or models. A combination of normal, bump, and displacement map nodes couldn't hurt.

True, but that's a limitation of how merchants are still stuck with supporting poser 4, not a limit of the software itself. Normal maps, like bumps are a 'fake' to simulate actual geometry on renderers that cant handle the performance hit of displacement. Firefly doesn't have this problem so there is no need to fake it, just use displacement itself, it may even render faster then bumps.

Quote - Honestly, while I do understand that it'd be nice to achieve photrealism now and again, I have to wonder at why everyone thinks this is the holy grail of 3D?

A talented modeler as yourself should  understand this better then anyone... Could you have gotten as good as you are without first understanding the human body as it is in reality ? All the countless studies you must have done, painstakingly recreating the shapes and the planes, all to learn and internalise the anatomy.. The reason why the toonish work (for example) in the Incredibles looks so authentic is that it also has this sort of solid base. Or in other words, you have to first know the rules before you can break them. Photorealism right now is the 'rule' that we as CG artists, are trying to understand. The surrealists, the abstracts and all that will come once the 'real' is understood to a degree that allows people to use it without the technical hurdles.

Not to mention that there are lots of benefits from a VFX viewpoint in having perfect photorealism. Actor salaries and temperaments are becoming increasingly nutty these days. As are the imaginations of directors/scripts and the hunger of the audience to see cooler and cooler stuff. All of which can means that CG photorealism fills a very tangible need in the industry. How else would you depict a half human, half squid undead pirate :)