I actually have the G2X Pro, which produces 200 lumens instead of 120.
-Bright
-Durable
-Protective twist cap to prevent accidentally turning it on.
-Really focused light beam.
-Not as small as they make it look in the picture.
-Unique non-rechargeable battery that's costly to replace.
I have the G2X as a backup to my normal headlamp. It's mostly for my night Time hiking/photography trips, when I need a bright and focused light to see my subject before I do long exposure shots. The light beam is very straight and focused, I love it.
It can also be used for self protection, as I learned when I first opened the box. I turned on the light and the first thing I did was accidentally point it at a co-worker straight in the eye. He literally stumbled back a few steps. lol.
This flashlight is the brightest, lightest, and toughest flashlight I've ever owned. I've used mine in some really rough conditions and it has performed admirably.
The batteries are expensive but last a long time under extensive use.