Just how good are festool lights ?

For a few years I've used a couple of Defender site lights like this -

http://www.screwfix.com/p/defender-e709150-2d-work-light-38w-230v/78401

and I doubt I am alone as they are cheapish, don't get hot and put out a decent amount of light.

However, as I get older and LED technology gets better I have started wondering just how much better the expensive battery powered Festool KAL 2 and the very expensive mains only Duo really are, and videos on YouTube don't really seem to...

Just how good are festool lights ?