My tests on the new build report a gaining of 0.3 - 0.4 db in avgPSNR measurements, both for 1pass vbr and 2pass vbr modes.
I like also to report that, like it was for latest official milestone, comparing a 1pass vbr encoding with a 2pass vbr version of the same clip results in a 0.4 db avgPSNR better for 1pass vbr mode clip; the test was performed on a classical 25 minutes anime episode without dropdupe.
Thanks for this new improvement, karl!