720p 4:4:4 10bit H.265/HEVC (encoded by x265) settings are almost the same as the H.264 encode avg qp 19 (lower by ~3-4 than H.264) ssim 23db (higher by 0.5db than H.264) encode size is lower by ~35%
visual comparison http://diff.pics/jvdjLaTlUhkD/1 (ignore the reversed filenames on 2 and 3)
note: this is just a test encode, i'm not saying x265 is any better than x264 or anything like that (as of now it's too slow to be super useful and it seems to smooth out grain/detailed textures sometimes due to broken psy)