TheBorg make decisions as a collective. As "Q Who" explains, this minimizes the kinds of mistakes that a single individual might make.
PairProgramming is a small-scale example of this kind of collective thinking.
Borg vessels do not have localized specialized subsystems. (For example, there is no centralized navigation system, or centralized defense system, etc.) Rather, this functionality is distributed throughout the vessel.
TheBorg waste no effort. Every action has a purpose, and nothing is done until it the need is demonstrated. For example, when the landing party from the Enterprise was exploring the Borg vessel, the Borg did not make any effort to interfere, because they did not perceive the landing party as a threat, and hence interference with the party was not needed.