Network Computing magazine has a cover story comparing heavy-duty document management systems—in this case via responses to an RFP they sent out with requirements for a hypothetical $10-billion market cap, NYSE listed company. 

While the scale of the project might seem to exceed what an "ordinary" law firm needs, the article is nonetheless worth a look for anyone with a public-company client:  Yes, they selected an "Editor's Choice" winner, but "any one [of the systems we reviewed] could be a lifesaver if litigation looms."