White Box, Or Big Names for Lower-End Servers?

LazloToth asks: "Those of us who manage small- to medium-size networks face the decision all the time: for the run-of-the-mill web, print, or storage server running on i386 architecture, should we buy HP or Dell, for example, or build it ourselves from commodity hardware and save some bucks up front? In my operation of fewer than 50 servers, one will see a mix of the two. For servers that take more abuse, I tend to buy the proprietary stuff. But not always. I wonder what experiences other admins and managers have had with do-it-yourself servers in a production environment, and whether they feel that white-box servers perform as well - - and last as long - - as anything else? What is the mix in your network of big-names to no-names?"