Earlier today I spent some time checking pages in Planet Bods in the Bobby, which is an accessibility validator, checking a website's HTML to see how accessible it is, and how it meets up to the W3C Web Content Accessibility Guidelines.
For Planet Bods, checking is a rather a slow process as the free version of Bobby only allows one check every minute, which means it takes forever to check a site where every page can have some major differences. Bods Central is easier as there's stricter templating, but for Planet Bods you just have to plough through it all, checking each page one at a time, being careful to not feed Bobby more than one page per minute, as that's all the free version will allow.
Unfortunatly Cynthia too is $99 and only allows one check online per minute, however the interesting thing about Cynthia is that it displays the results in the form of a table-based checklist, presumably so you can print it out and put big ticks next to things.
Which is great when you're printing out, but as a screen based metaphor, it doesn't work so well. it also didn't seem to clearly demark which bit of the report where checks to be done by the user, and those that had been automatically validated.
It seems to two types of data - what the site has passed and what it has failed, but it's all rather mixed up, meaning it's hard to spot things you need to correct.
Bobby in contrast only displays information you need to see - things you need to check for yourself and bits you need to fix, clearly marking which is which.
If you can get over Cynthia's presentation, then you'll find it a very capable validator abliet stricter than Bobby in that it rigorously enforces vaguer areas of the accessibility standards.
Still for me, despite it's failings, it does make spotting things you have to fix easy, to Bobby's the one for me for now. But with a few changes to the UI (perhaps as an option on top of the current version), Cynthia may well steal it's thunder.