Re: M3 and Pila\'s-what\'s the verdict?
Yes, this does work and it works well. There are a number of factors that contribute to this. The lower internal resistance of the li-ion batts. The fact that the li-ion batts don't sag as much under a load, etc.
The only modification that you will need to do is to wind another spring (slightly larger in diameter) around the negative contact spring on the Surefire lamp assemble. This gets around the problem of the Pila being a little fatter than a 123. It just so happens that the Pila spring used on the 3.7v lamp for the Surefire works very well for this purpose. Other wise, it's off to home depot or radio shack.
I think you can get into the whole rig for less than $100. It's well worth it. You might as well grab some 168S's too to feed those hungry regulated LED lights.