Acidrip is better
Honestly, I have trouble understanding why dvd::rip seems to be more popular than acidrip because as far as I have tried the former, the latter is much simpler AND faster.
First I find options present in acidrip are self explanatory and if not a tooltip appear when you're above explaining what the option does.
Second, ripping a dvd to a divx is really a matter of one click in acidrip whereas it seems to be more complicated in dvd::rip.
Third, acidrip allows you to rip subtitles wheither you encode dvd on the fly or not and I don't understand that limitation in dvd::rip
Last but bot least, acidrip encodes a 2 hours dvd in 50 minutes on my machine whereas I tried a on the fly encode (correct me if I'm wrong, but I guess this must be the fastest method) with dvd::rip and few minutes after launching (to let the software computes accuratly the remaining time), it displayed 3 hours remaining. I must admit I did not complete the process to see if it would have really taken 3 hours :-). The preceding test was made using ffmpeg codec.
I must admit dvd::rip seems to have some more advanced features than acidrip like cd burning, and whole bunch of video options not present in acidrip. But I feel most of the time the simple options present in acidrip are enought and if you need more you can always add some command line options that will be passed to mencoder. And above all I think the price that must be payed for those advanced features if too high if I consider the peformance and simplicity loss.