So I decided to test the noise in the latest daily build, and found I'm getting way more noise than the 1.7.2 release.
This scene is lit by a 1k env map, a 'sun' light (shining behind the surfaces in the images and a few small lights off camera which don't really add much illumination to the scene.
I cropped in to a small area, and I found that the 14 minute 4% noise render produced in 1.7.2 has a similar quality level to the latest daily 30 minute 7.5% noise render. Both using the new light solver. I understand that the different builds may display noise differently, but it's hard to not notice that time-wise, it took over twice as long in the latest daily to get something as good as 1.7.2.
So unless I'm doing something wrong, I'm looking at doubling my rendertimes for the new 2.0 release?