I have been using the Google site search (searches my site only) for quite a while and in doing some testing this morning, I found that the results for site search vs. regular Google searches are producing radically different returns. The site has 24,000+ pages. When I do exact phrase searches in regular Google, I always get the page I am searching for. In fact, I cannot find any pages that aren't in the index. However, when I do the exact same searches using the site search, it seems about 80% of the exact phrases I am searching for cannot be found.
So, using the site search seems to be a bit of a problem for my users. The site is a forum and because of all the information, finding exactly what you are looking for is paramount. I was using a paid monthly service that crawled the site daily and that seemed to work fairly well until the rates shot up for the number of pages crawled... that's why I moved to the Google site search. Anyone else familiar with this?