It may be easy to someone who's been on the site long enough, but for new users, the site is very cluttered and visually overloaded.
The search works, but that page lacks usability design. Displaying the whole "Advanced Search" form right away draws a user's eyes right to it due to the amount of space the inputs take up. You can easily miss the single input "simple search" right under the flashing ads. As users, we've quickly developed the ability to recognize ads by shape and placement alone on websites. So we mentally block them out. The search is so close to the top ads that many early users don't even see the simple search.
Anyway....sorry for the geek out. The functionality of the site isn't in question, it's the way it's presented and organized. There could be some major improvements to make everyday tasks easier for a user without taking away the "craigslist" style.