I rendered the V6 scene you sent me and, without changing anything, it rendered in 1m36s (V7 had rendered it in 1m40s, a 3% slower). I replaced the clouds by "low clouds 3", like before, and it rendered in 11s. V7 had rendered it in 8s, so V7 was faster by 25% with these clouds.

Interesting that with the original clouds V6 was 3% faster but with other clouds, V7 was 25% faster.

Like before, I reverted to the original clouds but decreased quality sliders ("Light" to -2 and "Clouds, Fog, Haze" to -1). V6 rendered it in 41s (V7 had rendered it in 45s, 9% slower).

So, conclusions? My conclusion is that there's no universal comparison V6 / V7 because these things are non linear. Some things are faster in one, other things are faster in other. So, it's very likely that someone compares V6 with V7 and draws one conclusion and someone else draws a completely different conclusion. For example, all that's needed is to change clouds for the conclusions to be completely different!

And this matches perfectly with the never ending discussions in forums about which is faster. No one is right and everyone is right. :-)

So, I say: forget about comparisons and just enjoy Vue 7. :-)