We have done real world tests with everything that is set out for HD.
If you wake up from a dead sleep in a dark or near dark house and turn on a 600 Lumen light you are toast. I know this from my own stupidity.
I have such a light next to my 1911 with the Tlr1 that I use when the search will take me outside. By the time I get to the door using the Tlr1 my eyes are coming around and there is little to no glare back off of white walls.
The HL is a bit too bright, be nice if you could adjust/half power it.
Glad to see I'm not the only one thinking this