Thanks for the replies!
Yeah as soon as I saw this light I was intrigued. On a rifle, I love the typical scout-type tubular lights, usually with a switch. But on these shorter AR pistols and carbine-ish setups (like some PCCs) they just take up too much space and weight. So I’ve put a pistol light on mine (posted in another thread), but this looks like a purpose built pistol/carbine light.
For the white lettering, some black permanent marker should fix that right up 
Good point about having to reach for the safety with a more vertical grip. I’ve heard the vertical is more comfortable on pistols.