I chose a modular power supply simply because I have a small case so there isn't much room to hide the spare cables. I also chose the power supply I have, the Cooler Master 850 W Silent Pro because it uses flat black cable designs where as some power supplies will have a bundle of yellow and black wires that are a little harder to run and cause a slight loss of airflow.
As ko888 stated though, the point where the cables plug in to the supply is one more point that could fail, although unlikely, it could happen.