Visual versus Text are just means to an end. What matters is how you apply the given form within a method or process.
A nice example of where hand code struggled and a visual language within the constructs of a formal method succeeded is the V22 Osprey compared to the BA609 Tiltrotor.
The Navy struggles to maintain the V22 and the vehicle has a total of around 40 deaths attributed to it. While the BA609 has far fewer operational hours, it also is more rigorously tested.
There are other notable examples of Model Based Design being more appropriate for large complex, mission critical, systems; Toyota's Prius, Curiosity, Dreamliner, etc.
A nice example of where hand code struggled and a visual language within the constructs of a formal method succeeded is the V22 Osprey compared to the BA609 Tiltrotor.
The Navy struggles to maintain the V22 and the vehicle has a total of around 40 deaths attributed to it. While the BA609 has far fewer operational hours, it also is more rigorously tested.
http://www.mathworks.com/videos/bell-helicopter-ensures-a-fl...
There are other notable examples of Model Based Design being more appropriate for large complex, mission critical, systems; Toyota's Prius, Curiosity, Dreamliner, etc.