Narrow-Bandwidth Television Association

I see that there is a concave topped LED called, 'The straw hat' instead of the usual convex top LED.
The straw hat has good light o/p and also with a very big angle of view (about 120 degree).
Has anyone used these straw hat LED's for any application and is the light constant over that wide viewing angle I wonder?

I have a string of little battery operated fairly lights that I use as the interior light for my Land Rover. They do seem to thro light out more evenly but I've not measured it properly...