I was so pleased to see a free version of WorldCat, but it got me to thinking. So, the free version is less functional than the paid-for version (otherwise, why pay for it?). Less functional.
I first thought of the thousands of times I've entered an exact title in WorldCat, specified it was a title, set the sort to relevance, and come up with pages and pages of nonrelevant titles (which don't even seem to share many, if any, words with my search) before finding the precise one that I want. And I thought, ugh, less functional. And then I thought of the thousands of times that I've had a patron ask for an obscure title or subject that our library had nothing on, and how I immediately went to WorldCat and was rarely disappointed. (Well, once I got to page seven with the precise title, that is.)
Ah, the intensity of a love/hate relationship. WorldCat: you can't live with it, you can't chuck it out the window as you sound your barbaric yawp.
Jessamyn West talks a bit more in-depth about her own love/hate of WorldCat.