I have a G2 with a 260 lumen replacement bulb on my rifle and it is MORE than enough to light up a room or search outdoors at 100+ yards. I also have the 15/320 lumen 6PX Pro for my hand light and again it is overkill most of the time. Actually you must be careful when using high lumen lights, if you shine it on a bright white or reflective surface you can easily accidentally blind yourself.
However, keep in mind the X series of lights, 6PX, G2X, P2X, etc... are NOT designed to be a mounted weapon light. I noticed this early on when i would set my 6PX Pro down on the table a little too hard while i was working and it would change from the 15 lumen to 320 lumen setting without anything touching the back button. In fact you can hold it in your hand and hit the frame with your other hand and it will change light settings or flicker on and off for a second. From what i read it doesnt have the necessary shock absorbing spring to be a weapon light, even the single output Tactical models can flicker when shooting. However, if its just intended to be a hand held light im sure it will work just fine, i know mine is awesome :)