Yeah ... but
... I would proffer that if you have 500,000 documents under management control, you have too many. You need to be more prescriptive with the term "document". By avoiding the noise, and being able to find what you are looking for from a small subset, quality and access are improved and benefits realised. Indexing everything, using something like the private Google Search Engine pointed at a fileshare, is just adding to noise. As usual, it is the humans that will tame the technology. I am keen to see how good Kendra is at getting me what I am looking for, rather than 5,950,000 hits for the term "storage latest WDC". I probably only want 3 out of those, sniff.