The 4.5" length makes it perfect size in my off-hand. During low-light firing it was easy enough to manipulate the light in my left hand while engaging targets with my weapon in my strong (right) hand. (Testing was done with the shown Kahr CW4543 .45ACP pistol) Identifying and engaging targets to at least the 15 yard line wasn't a problem. 120 lumens of light is plenty for such distances. Clearly seeing fine details from the 25 yard line was a bit more difficult for me, but that could be subjective. Others may have no issue from 25 yards or even further. The light's "throw" was easily farther than 50 yards.
This is one I have to give "two thumbs up". It's performance and versatility are impressive, especially given its overall size and the fact that it only uses one battery.
Let's move on now to the WX150.
Before I get into this let me reiterate my opinion about something (and this is just my opinion; many experienced and educated operators disagree with me): I don't believe you need a light mounted on your handgun unless you are a K9 handler or are on a Special Operations team. Over and over again in low light force-on-force training encounters we've seen that lights are bullet magnets in low-light environments. Bad guys will shoot at what they see. If all they can see is the light, they'll shoot at it. If it's centered roughly in front of your face, that means the incoming rounds are coming at your head. That said...
The test weapon was my Springfield Armory 1911 with an after-market rail attached. Installation only took a few moments. The WX150 came with the universal rail bar installed. A picatinny rail bar is also provided in the kit. Shown is the light mounted on the pistol.
Different from the HX120, the WX150 delivers 150 lumens of light from two CR123 3V batteries. If someone could do it, I'd prefer that the entire light body be narrower (it still bulges out on either side of the pistol), using only one battery and I'd be perfectly happy with 120 lumens. I know more is better, but maintaining the overall slim profile of the weapon has some benefits too.
Although brighter, the WX150 sacrifices (understandably and logically) some of the functionality of the HX120. Through the ambidextrous independent switches that can be operated with either hand you can have momentary on, constant on or strobe operation. Activing the momentary on or constant on is easy. Push down on the end of either lever and you get momentary on. Push either end up and you get constant on. A double tap and hold down on either end will give you strobe mode (as long as you hold the lever down), or a quick push down followed by a flick up will give you continuous strobe mode (until you push the lever back down).
The WX150 is also manufactured from hard anodized aluminum and seem pretty rugged. It took all the abuse I was willing to put my pistol through and kept on functioning. Reported run time on a set of batteries is 125 minutes - that's more than two hours of continuous use. When you consider how long it takes to add up all the momentary use into two hours of continuous use you can realize that 125 minutes of continuous use can be weeks, if not months, of use. Finally, according to the published material, weapons fitted with this light will fit in holsters normally designed to fit pistols with the Insight Tech Gear M3 - a fairly well known and popular weapon light.
So, two thumbs up for this one as well. If I'm going to put a light on my 1911, this one would serve well.
As always, search around for prices. Google is your friend and can save you some $$ when you decide to purchase either (or both) of these lights. For more information check out Insight Tech Gear on line.