Conclusion: The Brother MFC-5840cn offers a long list of features, including a network port, memory card slots, and the ability to work as a printer, scanner, and fax machine and copier. Unfortunately, it's weak in quality and performance.
Pros: Lots of features for the price. Built-in network port. ADF. Prints directly from memory cards. Works as a printer, scanner, standalone fax, and copier.
Cons: Relatively low output quality for an ink jet AIO. Slow performance, particularly over a network, both for its price and for ink jets in general.