This looks quite popular. Occasionally I saw some cyclists with lights comparable to car lights and I suspect they were this thing. However they seem to have little side visibility (not sure if they were this light, though).

Some questions:
1. Does it weigh less than a normal flashlight of the same or more lumens (each without batteries)? It looks light.

2. Beside the obvious mounting advantage, what are other advantages over a flashlight of the same lumens with the same batteries? Perhaps the lens is wider and so better?

3. Would it be convenient to carry in a bag when not in use?

Thanks.