Land Rover universals have a side thrust pad, no other brand has this feature and as a result they will fail under heavy/hard working conditions. Also all LR prop shafts have forged steel flanges, aftermarket (cheaper) flanges are cast iron and again will fail much sooner. Land Rover sliding joints are forged and are coated on the spline to reduce wear, whereas the aftermarket are not.
And a propshaft breaking whilst in use has the potential to throw the vehicle over, and this most certainly has happened, and it is not pretty!
Some people take the rist and go the cheaper aftermarket ones, but Defence have discovered all of the above the hard way and now dictate OE only I am told.