ScruffyNerfHerder said:

I haven't seen the preview but I'd just like to echo Jan's suggestion. CRF mode is designed specifically to be fast, efficient and high quality. If you're not aware of it, basically you set a quality level, with lower numbers being better, and CRF determines the lowest bitrate that can achieve that quality. Talking heads? Low bitrate. Explosions in the middle of a hurricane? High bitrate. It happens automatically and quickly, with only one pass. I've had great luck with it.
Keep up the great work! :)

CRF is not constant bitrate. I didn't see the preview, and I agree with you about CRF. :)