Ratecontrol has not changed, except in that it indirectly uses some results from B-adapt. r607 did change B-adapt. It was only sort of intentional: I had to change some parts of the algorithm in order to implement threading, but I tried not to change the results. If people conclude that quality-per-bitrate has suffered, I'll go and tweak it some more. Otherwise, just accept that CRF has changed scale (it always was arbitrary).