Are you using weapon, head mounted or hand held nvd's?
Having owned and shot both (on the white light end) , you can't go wrong either way. The wml's are a little more ergonomic, but I've had Fenix weapon lights, flash lights and recently purchased their 1000 lumen head lamp.
Zero regrets. That said, minimum 600 lumen. Don't compromise here. You'd be surprised how fast the darkness can swallow that up. In a cqb environment 600 is a weapon unto itself, but if you're hunting at night or stalking out in the open...you'll be wishing for that 1k.
Also, decide if you want a thrower or a flood...if you don't know what that means, hit up a little more DD before you take the plunge.
I'll tell you this, don't scrimp on this purchase. Buy once, cry once. Save up for the creme de la creme. My budget forays into night vision a few years ago we're dismal to say the least.
Streamlight recently came out with an IR only weapon light. Looks just like any of their TLR series but no markings.... Waiting for people to look at the front end while playing with the on/off toggle thinking "Why won't this turn on?"