I'm not sure what you mean by 'high drain'. It depends on the output and number of cells they use, but most bike lights are not high drain in terms of amps. OTOH, flashlight do tend to be high drain.

For most bike lights, I'd agree hi cap cells have the edge; for flashlights, LSDs can make more sense, mostly for the wear and tear on the cells and longer term performance of them.

By high drain I mean flashlights and the like. By low drain, as I mentioned earlier in this thread, I mean taillights and the like.