M3 was the fisrt SureFire flashlight I own. I got it in fall of 2000 at the crossroads gun and knife show. Actually I was not looking for the flashlights that day, but somehow this one caught my attention, and I was really impressed with its power. The dealer offered a good deal, so I decided to buy it, why not. Looked very cool and it was real bright. Well, it only lasts 20 minutes on 123 lithium batteries, that are quite expensive, but so what. High performance gadgets have their price too :)
General- SureFire is very well known flashlight (or as they say, high performance personal lights) manufacturer. As far as the design and quality goes everything in is a top notch: materials, fit, finish, attention to details. M3 was one of the few new flashlights designed in 2000. Although Y2K was still old millennium, not the new one, that doesn't really matter, the light is good and very powerful. M3 features aerospace grade aluminum body, coated with mil. spec. type III hard anodized finish. As SureFire claims with the knurled handle you can saw through the other aluminum flashlights. Although I've had my M3 for years by now that idea never crossed my mind. Probably because I have too many knives. As far as the scratch resistance of the finish goes it's ok, but not totally scratch proof. My M3 does have scratches and scuff marks even though I was not using it heavily, for obvious reasons. So, if the finish and looks matter to you, better take good care of your SureFire M3.
In the end, I like M3 design. Sturdy and easy to use. Either turn the tail for constant on, or depress the tailcap button for momentary on off. As I've mentioned above with high output MN11 xenon lamp the lifetime of one set of batteries is approx. 20 mins. Which is not all that much, however considering the designated use of M3 that is not too small either.
In addition; M3 is tough enough to be used as a weapon light. It can withstand repeated shock from high caliber weapon recoil. Well, we wouldn't expect any less from a decent weapon light ;)
Beam- As I've mentioned above M3 produces 225 lumens for 20 minutes. Based on SureFire data that is 15 times brighter compared to any 2D cell flashlight out there, apparently incandescent. In reality M3 is exceptionally bright light, especially for its size. Don't try to look at the beam directly, it's definitely not good for your eyes, really painful, trust me. At low light conditions M3 can easily put someone's eyes out of commission for several minutes if pointed into them.
The beam on M3 is always focused. You can not change it[focus]. It's optimized for producing a bright spot which is natural for tactical flashlight.