Do we need a 50.6MP image? Canon thinks so, as it releases two fulll-frame 5D models: the 5DS and the 5DS R.
First, a look at the difference between the two models. The 5DS R has the ability to enabling a "cancellation effect" of the low-pass filter, which should yield a sharper image out of camera. Canon warns that using this effect can increase moire and artifacts. There's no such thing as a free lunch, as the saying goes.