Neil
That is one of the common rapid methods used in the cheaper cnc's, even my Shadow/Bandit controllers do that. It does take some care sometimes, because the 45 degree dogleg can sometimes inadvertantly run the tool into a shoulder or a clamp.
I cannot imagine that it is faster than a straight line 3 axis rapid move, but there must be a saving of 10 cents worth of semiconductor to justify it from the manufacturer's viewpoint.
