For video work in small areas they are brilliant due to no heat given off. The other advantage is that you can see the lighting effect before you take the image. The disadvantage is the light output isn't as much as flash so you end up getting them closer or adding more, which then brings into question the size of the light source. Whilst you can turn them down, I'm not sure if they do modifiers now, but most led panels have somewhere between a 40-60 degree beam angle.