ITI & Streamlight have a winning product with their M-3.
Many people use the M-3 rather then the SureFire P101. This is down to price, light-weight and therefore the M-3 attaches to some handguns without an adaptor which is important to people who have holsters that can't hold a handgun with SureFire's adaptor attached.
There are some handguns now that are built to high enough standards to accept a SureFire WeaponLight. It's all about flex in the gun or something - the rails on many handguns aren't rigid enough. I hear that many firearms are being designed now with standard Picatinny rails so that users can mount accessories such as WeaponLights on them.
In general I get the impression that SureFires are specialist illumination tools compared to Streamlight's mass-market alternative.
What is good is that having a weapon mounted light; the training and the ability to use it correctly does make a difference.
To be quite frank, the Joe Public who buys an M-3 over a P101 and spends the difference on more training is making a good use of his available resources.
Again, it is fine by me if Joe can swap his M-3 between this Glock and his Remington 870 shotgun because he can't afford two illumination tools, why should I shout at him to get a dedicated 618FA if it means he won't have access to a light on his handgun?
At the end of the day, I would rather Joe had a light on his weapon because I think its a good idea to know what you're shooting at.
Regarding the M-3's output - ones I have seen have not been as good as SureFire's P60 Lamps. As with the Scorpion lamps, bulb life is less than SureFires. Reliability is good but just as with any bulbs, it's difficult to get an accurate overview from just the internet.
What I do find hard to understand are those who get an M-3 for their shotgun, carbines or submachineguns etc. This is where SureFire stands clear above the rest. Dedicated and Modular WeaponLights that give you high power, great switching and massive interchangeability.
Is the M-3 better than SureFire?
For some handguns, for some users, for some applications, yes.
In general, the M-3 is not aimed at the same market that SureFires are.
At least that's my opinion. I hope it isn't too offensive.
Al