I just got the Lite-On DH-401S-08 and started experimenting with backing up my blue-ray discs. My main reason for doing this is so that I wouldn't have to hear the noise of the drive while I'm watching a movie.
I haven't found the best bitrate for divx compression yet but I wanted to post my findings. The only big difference in quality I could see after comparing side by side a couple of times is when there is fast movement, you will see some blurring and blocks but it's really not that bad. I am going to try 2-pass encoding tonight and maybe bump up the bitrate a bit to see what I get. (1-pass took about 5 hours to compress, 2-pass 8 hours)
Another major advantage is the h.264 decoding almost takes up all my cpu while divx only used about 11~50%.
TS file after tsremux twice with 1 Dolby audio stream: 20,491,457,620 bytes
4000kbps 1-pass divx compression: 3,450,216,208 bytes
(both of these files are the same resolution and length)
Please post your findings and some comparison comments.