While we're on the topic of "every quadrotor should ____", how about the improved efficiency of this design?

http://spectrum.ieee.org/automaton/robotics/aerial-robots/ir...

See also:

http://www.itee.uq.edu.au/bme/pounds

... and, if you have IEEE privileges, the paper is here:

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6...