I have no problems with OBK or Injected Opposed big Lyc's method for navigation - in fact many years ago when I regularly flew much bigger aeroplanes than I currently do, it was the method that I employed.
My only concerrn is that so much time is spent head in cockpit that it is easy to fail to keep a good lookout.
I am not for one second suggesting that OB or IO540 do not keep a good look out.
Stik