I have bought the (what's now called the C2-HA) and I think it's an amazing flashlight. I have also field-tested the C2-BK for the durability of the black anodisation. Whilst both forms of the C2 are excellent, the new M2 takes the durability and toughness of flashlights to a whole new level.
I want to make this vert clear:
The new M2 is one of the World's greatest flashlights.
This flashlight has a "Shock Absorbing System" (S.A.S.) which protects the Lamp Module. The ability of this S.A.S. is simply outstanding, and amazing!
I have not managed to damage or break a Lamp Module during my field-testing of a proto-type of this new M2.
Infact, the Shock Isolation and the Hard Anodising make this one of the toughest flashlights that I know. For an Aluminium flashlight, to be in the same league as a "polymer" flashlight such as Pelican, really surprised me.
The M2's pocketclip and CombatGrip, not to mention the ability to have a high output Lamp Module, make it possibily the highest spec flashlight ever.
I attach the M2 to my belt, but it's not a thick weapon's belt (or whatever the term is)
I would say my "Ben Sherman" leather belt is about 3cm thick, and the M2 attaches just fine.
Whilst I would agree with Brock's suggestion of the E2 over the C2, I would have to say that the E2 is not a flashlight specifically designed to be used in the a tough, harsh and abusive environment. I would always go for the Military Level III Hard Anodise (HA) rather than the black coating as the difference in durability and toughness is incredible!
If you're gonna get the E2, the GM (gun metal) coating should not be expected to withstand the same abuse as the HA. It looks different, and I think cool, but it's form rather than function.
It's great that SureFire has all these options. Personally, I will soon have both the E2 and the M2. I'll use the E2 as I use the E1 now - constant-carry flashlight. The M2 is for times when I require the very best from my tools in conditions which most flashlights will fail.
I hope you find the flashlight for you.
Al
