DVDRB + CCE is an encoder and will give a superior result to both Shrink and Clone.
Shrink will take a shorter time than RB and longer than Clone but gives very good results as well
Clone is VERY quick and gives good results if the compression/bitrate are not too bad and if you don't have a 2406598" home theater.
that's the short version.
i say you should burn the same film using all three (preferably something with high action) and paly them back on your system comparing the three and determine what is best for you.
i watch movies on my 17" computer monitor or a 25ish" TV so I'm quit happy with clonedvd and the time savings i get.
if i have anything that wants to ocmpress below 75% i remove parts in clone then change the target to dvd+R DL. this removes the parts i don't want but saves everything else so i can keep the menus while i transcode with shrink (deep analyis, sharp). otherwise, if i remove unwanted parts in shrink, i lose menus.
i think shrink and clone work well together (and apart!). they each have features that i wish the other had. unfortunately all of the features cannot be combined into one due to reasons that are stated in the numerous threads that have been posted about this topic.
another thing to keep in mind is that the powers that be have hinted at clonedvd containing an option to ENCODE rather than transcode sometime in the future. If/when this happens, clonedvd2 will probably outperform shrink quality-wise.
remember quality has to do not only with compression but also bitrate of the original and this is a subjective area of debate...try them all for yourself!