I really don't think that an unbiased render engine is what we need in vue (don't get me wrong, Lux IS a great render engine and it produces amazing images).

But ... the complexity of an average vue scene would produce render times well over what a normal user with a normal computer can bear (I have a dual xeon w3690 and unbiased renders still take a lot of time with scenes that are not even close to the complexity of an average vue scene).

What I would love instead is an energy conservative shader (something like the arch and design material in 3ds max for example). This kind of material is physically correct without being unbiased.

You can get the same amount of realism you get from an unbiased render engine but at a fraction of the render time (it's of course not as "easy" to use)

And one thing, before we can render anything really photo realistic in vue, the gamma workflow still need some fixing :P