The "Narrow Search" column that appears on the right is concise and clear - less confusing than the clusters used in Aquabrowser, if somewhat less happening and visually appealing to the MySpace generation.
For librarians who like cataloguing - and let's face it, who doesn't? :) - this look should appeal, as the layout looks comfortingly like Subject Headings.
These links work pretty effectively and Similar Items lists are also interesting - only as wrong as Amazon or LibraryThing, but not bad.
I thought I'd throw "armadillo" at the National Library's VuFind and the results were fascinatingly eclectic, including a picture, but somehow almost completely wide of the mark. Yes, it is the name of pieces of music, corporate authors and the rest, but it might have been nice to have had the term "Animals" at least appear in the subject area.Poor old armadillo - the brand has been widely appropriated, but the beastie himself (apart from the one image) appears to have vanished from this main page.
Perverse, I know, but it gives some idea of the foibles of this kind scattershot approach.
