Comparison image on the first page is updated with Maxwell version 1.0.
Seems like the noise doesn't really clear any faster.
But, on the other hand, the colours are very rich, and multi-light is amazing! I actually don't think I could go back to another renderer that doesn't have that feature!
I had to use the complex IOR copper material. The tow other copper materials included in the materials database were far inferior to the complex IOR one. They either had weak caustics or colour. Perhaps I just need to spend more time tweaking the material, but that's a little counter-productive....