I've published the x264 options in my
benchmark. Under this configuration, both encoders have near (x264 is slightly better) output quality. The CPU I used costs about US$ 195, the GPU (display adapter with 896MB onboard GDDR3) I used costs about US$ 235.
PS1: For serious encoding, I myself use x264.
PS2: I don't know and have no relationship with St Devious and I don't think he can benefit anything by advertising the crappy encoder. I just saw this post by a back-link to my blog.