LED Replacement bulbs?
The side-emitter has more flood and artifacts and the Lambertian has a cleaner brighter white shot. The lumen output is about the same. The main difference is with the Side-Emitter all the light from the LED is directed out the sides towards the reflector. The Lambertian sends the light in all directions equally. So the pattern you see with the Side-Emitter is dependent on the size and shape of the flashlight reflector. The Lambertian sends light out the front of the flashlight as well as sending light towards the reflector.