SMOORE  Curiouser and curiouser...

Here's a third product that looks very similar to the other two:

http://ezinearticles.com/?Wondershare-ISkysoft-AimerSoft---Three-Best-DVD-Ripper-For-Mac-Reviewed&id=1507051

At least one (Aimersoft) also sells a 4-piece suite which includes Mac DVD Ripper, Mac Video Converter, Mac DVD Copy and Mac DVD Creator:

http://www.aimersoft-mac.com/dvd-studio-platinum-mac.html

I tried the Aimersoft DVD Ripper demo and it seems quite capable (though it did crash more than once), but I'm reluctant to shell out any money without some clarification as to what is what and whose is whose.  
(Version 1.8.2.1)