Can you share your parameters and results @nonsuch?

I'll show you an example:

H265: -movflags faststart -c:v libx265 -crf 27 -pix_fmt yuv420p -preset medium -tune fastdecode -auto-alt-ref 0 -metadata:s handler_name=ClortVids
FILESIZE = 1.996 MB

H264: -movflags faststart -c:v libx264 -crf 23 -pix_fmt yuv420p -preset medium -tune fastdecode -auto-alt-ref 0 -metadata:s handler_name=ClortVids
FILESIZE = 3.933 MB

Results: h265 on top, h264 on bottom

Notice the color quantization, pixel blocking.
Video results:
H264 http://0x0.st/-fL3.mkv
H265 http://0x0.st/-fL4.mkv

At least with these parameters H264 looks worse even at twice the filesize of H265.

Cpu use with mplayer vieweing 24fps 960x540 is at 55-75% with h264 and 75-105% with h265. The encoding time for h265 is about 10x slower.