From what I can gather, the 12PM and 12ZM were designed to be used for seconds rather then minutes as "Tactical Entry" lights and Force Options in situations where the smallest, most light-weight, excellent quality, most powerful illumination tool is required, and consider the uses for which is was designed, where running costs are not really a factor.
The 12PM eats batteries like a staving cookie monster eats cookies!
Using the best 132A batteries which up until the SF123A, where Duracell Ultra DL123As will give you that peak beam for longer.
The batteries from my 12PM and other high powered SureFires are 'sucked dry' and the obvious benefits and advantages of the MN11 225Lu beam in a SureFire M1xx WeaponLight on your handgun mean that SureFire provide illumination tools for situations where rechargeable versions are just too big, and too heavy.
My opinion, and I would love to test this, is that the M1xx with MN11 is the brightest flashlight per unit volume.
I would also like to find the brightest flashlight in terms of output compared to a host of factors including runtime, volume, weight and maybe a cost factor too.
Anyone who wants to pay me to do this is most welcome. I can start right now.
Al